Stats by Source
Global, split by cell line (COSMIC CL / DepMap / PubMed) vs tissue (COSMIC primary tissue)
Global = all mutations for this gene across every source.
Cell line = COSMIC Cell Lines Project + DepMap + PubMed.
Tissue = COSMIC primary-tissue (patient tumour) samples.
Global can exceed cell line + tissue: COSMIC tissue-derived models sit only in global, and a peptide can be shared across both.
| Global | Cell line | Tissue | |
|---|---|---|---|
| Mutations | 442 | 38 | 328 |
| Samples | 201 | 18 | 149 |
| Peptides | 116 | 19 | 105 |
Function
C4A · Complement C4A (Chido/Rodgers blood group)
This gene encodes the acidic form of complement factor 4, part of the classical activation pathway. The protein is expressed as a single chain precursor which is proteolytically cleaved into a trimer of alpha, beta, and gamma chains prior to secretion. The trimer provides a surface for interaction between the antigen-antibody complex and other complement components. The alpha chain is cleaved to release C4 anaphylatoxin, an antimicrobial peptide and a mediator of local inflammation. Deficiency of this protein is associated with systemic lupus erythematosus and type I diabetes mellitus. This gene localizes to the major histocompatibility complex (MHC) class III region on chromosome 6. Varying haplotypes of this gene cluster exist, such that individuals may have 1, 2, or 3 copies of this gene. Two transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Nov 2014].
Isoforms & Proteins
2 transcripts · UniProt mapping is sequence-verified (AA-safe)
Each Ensembl transcript (ENST) this gene is mutated on, with its matched UniProt accession.
The mapping is sequence-verified: the UniProt sequence is identical to the transcript translation, so amino-acid positions line up exactly. A * marks an unreviewed (TrEMBL) entry.
Counts are mutations and unique mutant peptides on each transcript.
Gene Properties
Recurrent Mutations
Top recurrent amino-acid changes along the protein · needle height = number of mutations
A lollipop / needle plot – the standard way to show recurrent mutations along a protein (as used by cBioPortal and MutationMapper).
X-axis = amino-acid position in the protein.
Needle height & head size = how often that exact amino-acid change was observed (its recurrence). Tall/large heads are mutational hotspots.
The most recurrent changes are labelled; hover any needle for the change, position and counts.
Mutation Distribution
Where C4A is mutated · all tissues, split by cell line vs tissue
How many mutations in C4A were found in each tissue, across the whole database.
Each bar is a tissue (cell-line and tissue names are merged to the standard tissue), split into cell line and tissue (patient tumour) contributions.
This shows the cancer-context where this gene is recurrently altered.
GTEx Expression
Median TPM across 54 healthy tissues
Median gene expression (TPM) in normal, non-cancer human tissues from the GTEx project.
Useful for judging tumour specificity – a strong neoantigen target ideally comes from a gene with low expression in healthy tissues.
Scroll or drag the mini-axis below the chart to browse all tissues.
Mutations
All 442 mutations in C4A
Every mutation record for this gene, across all samples and sources.
The Sample column links to the cell line (cell-line samples) or the tissue type (tissue samples).
Use the Type / Source filters, the search box, and column sorting to explore; each CAN-IMMUNE ID opens the full mutation & peptide view.
| ID | Sample | Transcript | AA Change | CDS | Type | Source | Peptide |
|---|