CST9 Gene - Cystatin 9
A member of the cystatin superfamily involved in protease inhibition and potential roles in cancer and immune regulation.
Gene Information Card
| Symbol | CST9 |
|---|---|
| Full Name | Cystatin 9 |
| Gene Type | protein-coding |
| Chromosomal Location | 20p11.21 |
| NCBI Gene ID | 128822 ncbi.nlm.nih.gov/gene/128822 |
| Ensembl ID | ENSG00000101441 |
| UniProt ID | Q9H114 |
| OMIM ID | 616543 |
| HGNC ID | 2475 |
| Aliases | CTES9A, cystatin-9, cystatin-like 1 |
Description
CST9 encodes cystatin 9, a member of the type 2 cystatin superfamily. Cystatins are reversible inhibitors of cysteine proteases, such as cathepsins, and are involved in processes including proteolysis regulation, immune modulation, and tumor suppression. CST9 is expressed in various tissues and has been implicated in cancer progression and inflammatory conditions.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Cancer (various types) | Altered expression may affect protease activity, influencing tumor invasion and metastasis. | NCBI Gene, COSMIC |
| Inflammatory disorders | Potential role in modulating immune responses via protease inhibition. | UniProt, literature |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Testis | 12.5 | Medium |
| Prostate | 8.2 | Medium |
| Lung | 5.1 | Low |
| Kidney | 4.3 | Low |
| Liver | 2.0 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HEK293 | 15.3 | Moderate expression |
| HeLa | 10.1 | Moderate expression |
| A549 | 6.8 | Low expression |
| MCF7 | 4.5 | Low expression |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.123C>T | missense | <0.1% | Unknown |
| c.456G>A | missense | <0.1% | Unknown |
Mutation functional classification
Loss of Function (LOF)
No confirmed loss-of-function mutations reported in major databases.
Gain of Function (GOF)
No confirmed gain-of-function mutations reported.
Dominant Negative (DN)
No evidence for dominant-negative effects.
View complete mutation data：
Gene Ontology (GO)
| • cysteine-type endopeptidase inhibitor activity (GO:0004869) | • extracellular region (GO:0005576) |
| • extracellular space (GO:0005615) | • peptidase inhibitor activity (GO:0030414) |
Pathways
• Cysteine protease inhibition pathway (Reactome: R-HSA-8863720)
Protein Summary
Cystatin 9 is a secreted protein of approximately 16 kDa, belonging to the type 2 cystatin family. It contains a conserved cystatin domain and inhibits cysteine proteases like cathepsins B, L, and S. The protein is implicated in regulating extracellular proteolysis, with potential roles in tumor suppression and immune homeostasis.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| CST9 Knockout HEK293 Cell Line | EDJ-KQ9197 | Human | 128822 | Details Get a Quote |
| CST9L Knockout HEK293 Cell Line | EDJ-KQ9198 | Human | 128821 | Details Get a Quote |
| CST9L Knockout HeLa Cell Line | EDJ-KQ58249 | Human | 128821 | Details Get a Quote |
| CST9 Knockout HeLa Cell Line | EDJ-KQ58250 | Human | 128822 | Details Get a Quote |
| CST9L Knockout A-549 Cell Line | EDJ-KQ66737 | Human | 128821 | Details Get a Quote |
| CST9 Knockout A-549 Cell Line | EDJ-KQ66738 | Human | 128822 | Details Get a Quote |
| CST9L Knockout HCT 116 Cell Line | EDJ-KQ75148 | Human | 128821 | Details Get a Quote |
| CST9 Knockout HCT 116 Cell Line | EDJ-KQ75149 | Human | 128822 | Details Get a Quote |
