FOXA1 (Forkhead Box A1): Pioneer Transcription Factor in Hormone-Dependent Cancers

A master regulator of chromatin accessibility and hormone receptor signaling, frequently altered in breast and prostate cancers.

Gene Information Card

Symbol FOXA1
Full Name Forkhead Box A1
Gene Type Protein coding
Chromosomal Location 14q21.1
NCBI Gene ID 3169 ncbi.nlm.nih.gov/gene/3169
Ensembl ID ENSG00000129514
UniProt ID P55317
OMIM ID 602294
HGNC ID 5021
Aliases HNF3A, TCF3A, MGC33105

Description

FOXA1 (Forkhead Box A1), also known as HNF3A, encodes a member of the forkhead class of DNA-binding proteins. As a pioneer transcription factor, FOXA1 binds to condensed chromatin and opens it, facilitating the recruitment of other transcription factors, particularly hormone receptors like estrogen receptor (ER) and androgen receptor (AR). It is essential for normal development of the liver, lung, prostate, and mammary gland. FOXA1 is frequently mutated or overexpressed in several cancers, especially hormone-dependent breast and prostate cancers, where it influences tumor progression and therapy response.

Disease Associations

Disease category Pathophysiological mechanism Genomic evidence
Breast Cancer FOXA1 mutations and overexpression alter ER binding and gene expression, promoting tumor growth and endocrine resistance. COSMIC, ClinVar, multiple studies
Prostate Cancer FOXA1 mutations and gene fusions (e.g., with AR) enhance AR signaling and drive castration-resistant prostate cancer. COSMIC, ClinVar, multiple studies
Hepatocellular Carcinoma FOXA1 overexpression is associated with poor prognosis and may promote epithelial-mesenchymal transition. COSMIC, literature
Lung Cancer FOXA1 expression is elevated in lung adenocarcinoma and may contribute to tumor progression. COSMIC, literature

Expression Profile

Tissue Expression
Tissue nTPM level
Breast 20.1 Medium
Prostate 15.3 Medium
Liver 12.4 Medium
Lung 8.2 Low
Kidney 5.1 Low
Cell Line Expression
Cell Line nTPM Notes
MCF7 (Breast) 35.2 ER-positive breast cancer cell line
LNCaP (Prostate) 28.7 Androgen-sensitive prostate cancer cell line
HepG2 (Liver) 22.4 Hepatocellular carcinoma cell line
A549 (Lung) 10.3 Lung adenocarcinoma cell line
Data source:Human Protein Atlas(proteinatlas.org)

Mutations & Variants

Hotspot Mutations
Variant Type Frequency Functional Description
R219C Missense ~2% in breast cancer Alters DNA binding affinity
F266L Missense ~1% in prostate cancer Affects protein stability
G259V Missense ~1% in breast cancer Impairs forkhead domain function
Amplification Copy number gain ~10% in breast cancer Increased expression
Mutation functional classification

Loss of Function (LOF)

Rare truncating mutations that impair DNA binding or nuclear localization, leading to reduced pioneer activity.

Gain of Function (GOF)

Missense mutations in the forkhead domain that enhance chromatin opening and alter target gene selection, promoting oncogenic signaling.

Dominant Negative (DN)

Some mutations may produce a protein that competes with wild-type FOXA1, disrupting normal pioneer function.

Gene Ontology (GO)

• DNA-binding transcription factor activity • Chromatin binding
• Sequence-specific DNA binding • Regulation of transcription by RNA polymerase II
• Cell differentiation • Response to hormone

Pathways

• Estrogen receptor signaling
• Androgen receptor signaling
• Chromatin remodeling
• Developmental biology

Protein Summary

FOXA1 is a 472-amino acid protein with a conserved forkhead DNA-binding domain. It binds to the consensus sequence 5'-T[G/A]TTT[G/A]T-3' in the minor groove of DNA, acting as a pioneer factor to open condensed chromatin. This enables recruitment of hormone receptors and other transcription factors. FOXA1 is critical for normal organ development and is implicated in cancer progression, particularly in hormone-driven tumors.

Related Products

Product name Cat.No. Species Gene ID
FOXA1 Knockout HEK293 Cell Line EDJ-KQ2840 Human 3169 Details Get a Quote
FOXA1 Knockout A-549 Cell Line EDJ-KQ23832 Human 3169 Details Get a Quote
FOXA1 Knockout HCT 116 Cell Line EDJ-KQ23833 Human 3169 Details Get a Quote
FOXA1 Knockout HeLa Cell Line EDJ-KQ23834 Human 3169 Details Get a Quote

Biological Process

Gene Expression and Regulation: A Complete Technical Map from Mechanism to Validated Cell Models

Promoters, Enhancers and 3D Genome Organization: How to Validate Regulatory Relationships with Editing and Interference Tools

Enhancer–Gene Pair Validation: A Complete Technical Roadmap from Candidate Element to Publishable Evidence

CRISPR Deletion vs CRISPRi for Regulatory Elements: Choosing by Evidence Requirement

Building Reporter Cell Lines for Quantitative Regulatory Readouts

TAD Boundaries and Insulators: What They Constrain and What They Do Not Prove

Super-Enhancers and Cell Identity: Design Strategies for Functional Validation

Validating Transcription Factor Binding Sites: From ChIP Peaks to Functional Evidence

From GWAS Signal to Causal Variant: Functional Validation of Non-Coding Risk Loci

Enhancer Redundancy and Shadow Enhancers: Designing Controls That Catch Compensation

Core Promoter Elements: Dissecting Initiator, TATA and CpG-Island Promoters

Single-Cell Multi-Omics for Mapping Regulatory Elements in Heterogeneous Tissues

How Many Candidate Enhancers Can a Single CRISPRi Screen Test?

What Fragment Size Should Be Deleted When Removing an Enhancer?

How to Design sgRNAs for Enhancer Deletion

What Effect Size Counts as Biologically Meaningful in Enhancer Studies?

What Controls Are Required for a Regulatory Element Knockout?

How to Confirm a TAD Boundary Is Functional

Can ATAC-seq Alone Identify Functional Enhancers?

What Is a Shadow Enhancer, and Why Does It Break Your Screen?

How to Report Negative Results in Regulatory Element Studies

Distance Window or TAD Boundary: Which Constraint Matters More?

DNA Methylation, Histone Marks and Chromatin State: Selecting and Validating Epigenome-Editing Tools

CRISPRoff, dCas9-TET and dCas9-p300: A Practical Comparison for Targeted Epigenetic Editing

How Long Does Epigenetic Silencing Last? Stability, Inheritance and Reversibility

DNMT and TET Knockout Cell Lines: What Phenotypes to Expect and How to Verify Them

Reading Chromatin Accessibility: From ATAC-seq Peaks to Functional Hypotheses

Histone Modification Writers, Readers and Erasers: A Knockout Map

Assessing Off-Target Effects in Epigenetic Editing

Single-Cell Epigenomics: scATAC-seq and scChIP-seq in Development and Disease

Spatial Epigenomics: Mapping Modifications In Situ

Epigenetic Clocks and cfDNA Methylation as Biomarkers

Imprinting and Parent-of-Origin Expression: Why Allele-Specific Regulation Matters

What Is CRISPRoff and How Does It Differ From dCas9-KRAB?

How Stable Is Epigenetic Silencing Across Cell Divisions?

Which Cell Line Is Best for Studying DNA Methylation?

How to Validate a DNMT1 Knockout Clone

What Is a Differentially Methylated Region (DMR)?

Do Epigenetic Edits Create Off-Target Methylation Changes?

How to Link ATAC-seq Changes to Gene Expression Causality

What Is Histone Lactylation and Why Does It Matter?

How to Design a Single-Cell ATAC-seq Experiment

Can Epigenetic Editing Restore a Silenced Gene?

lncRNA, miRNA and RNA Modification: A Complete Path from Function Prediction to Phenotype Validation

Why lncRNA Knockouts Often Show No Phenotype — and How to Design Around It

lncRNA Functional Validation: Knockout vs Knockdown vs Antisense Oligonucleotides

m6A Writers, Readers and Erasers: Mapping and Testing RNA Modification Function

miRNA–Target Validation: Evidence Beyond Luciferase Reporter Assays

RNA-Binding Protein Screens: Design, Readouts and Hit Prioritization

Alternative Splicing Regulation: Isoform-Level Validation Strategies

Circular RNA Biology: Detection, Function and Experimental Pitfalls

RNA Localization and the Spatial Regulation of Translation

Why Does an lncRNA Knockout Often Show No Phenotype?

Knockdown vs Knockout for lncRNA: Which Is More Informative?

How Long a Fragment Should Be Deleted for an lncRNA Knockout?

Which m6A Antibody Should I Use for MeRIP-seq?

What Is the Difference Between RIP-seq and CLIP-seq?

How to Validate a miRNA Target Without a Luciferase Assay

How Many Isoforms Must an Alternative Splicing Study Cover?

Is Circular RNA Detection Reliable Across Platforms?

How to Verify RNA Localization Experimentally

What Proportion of Annotated lncRNAs Are Functional?

CRISPR Knockout, Knock-In, Activation and Screening: A Strategy Matrix for Regulatory Research

Knockout, CRISPRi or Base Editing? A Six-Dimension Decision Matrix

Genome-Wide CRISPR Screening: Library Coverage, MOI and Readout Design

Perturb-seq and Single-Cell Screens: Linking Perturbation to Transcriptional Programs

Essential Genes and Lethal Phenotypes: How to Study What You Cannot Knock Out

Base Editing and Prime Editing in Regulatory Research: When Precision Beats Deletion

Quantifying Editing Efficiency and Off-Target Events: A Practical Framework

Choosing a Cas9 Variant and Delivery Format for Your Cell Type

Multiplex Editing and Temporal Control of Gene Regulation

How Much Library Coverage Is Enough for a Genome-Wide Screen?

What MOI Should I Use for a Lentiviral CRISPR Library?

How to Screen a Non-Proliferative Phenotype

How to Study an Essential Gene with CRISPR

What Is the Difference Between Base Editing and Prime Editing?

How to Measure Knockout Efficiency in a Cell Pool

How to Design a Multiplex Knockout Experiment

Which Cas9 Variant Works Best for AAV Delivery?

What Is a Safe-Harbor Locus for Knock-In?

How Many Clones Must Be Screened to Confirm a Homozygous Knockout?

From Pathway to Model: Validation Paradigms in Cancer, Neuro, Immune and Metabolic Research

Oncogene Dependency and Synthetic Lethality: Building the Right Validation Model

Enhancer Dysregulation in Neurodegeneration: Lessons from Glial and Neuronal Models

CAR-T and ADCC Target Validation: Engineering Immune Cell Lines for Functional Assays

Hippo, WNT and PI3K: Validating Pathway Nodes with Knockout Cell Lines

Drug Target Validation: A Standardized Workflow from Hit to Model

Metabolic Pathway Enzymes: Building Loss-of-Function Models

Gene Editing in iPSC and Organoids: Constraints, Timelines and Readouts

Disease-Associated Non-Coding Variants: From Risk Locus to Cellular Phenotype

How to Validate Pathway Activation After a Knockout

How Long Does iPSC Gene Editing Take?

How to Edit Organoids Without Disrupting Their Structure

Which Cell Line Models ADCC Most Reliably?

How to Build a Synthetic Lethality Screen

What Is a Good Model for Enhancer Dysregulation in Neurons?

How to Validate a Drug Target Before Committing to a Programme

Why Does My Knockout Cell Line Lose the Phenotype After Passaging?

How to Choose Between Human and Mouse Cell Models

What QC Documentation Should Accompany a Custom Cell Line?

Gene Knockout Feasibility Self-Assessment: Ten Constraints That Decide the Project

Pathway-to-Model Reference Chart: Key Genes × Recommended Cell Models

Working with Hard-to-Transfect Cells: A Delivery Strategy Guide

How We Validate Knockout Clones: PCR, Sanger and Western Blot in Combination

Custom Knockout Cell Line Service: Strategy Design, Single-Cell Cloning and Triple Validation

Stable dCas9-KRAB and Cas9 Expression Cell Lines

Knock-In Reporter Cell Lines for Regulatory Readouts

Genome-Wide CRISPR Library Screening Service

Services Comparison: In-House vs CRO vs Off-the-Shelf Cell Lines

Epigenetic Editing Enters the Clinic: What It Means for Research Models

AI Sequence Models in Regulatory Genomics: Hype, Reality and Where They Help

Live-Cell Imaging Rewrites the Rules of Transcriptional Regulation

Spatial and Single-Cell Multi-Omics: The Next Validation Frontier

From CRISPR Screens to Programmable Medicine: A Five-Year Outlook

Contact Us
*
*
*
How did you hear about us: