This gene encodes the final component of the complement system. It participates in the formation of the Membrane Attack Complex (MAC). The MAC assembles on bacterial membranes to form a pore, permitting disruption of bacterial membrane organization. Mutations in this gene cause component C9 deficiency. [provided by RefSeq, Feb 2009]
Forensic Context
A study in human blood plasma demonstrated that the C9 (complement component C9) was significantly upregulated with age and was part of a set of 21 proteins used to build accurate chronological age-predictive models [Salignon et al. DOI:10.18632/aging.204787]. The protein-based model achieved an R² of 0.59 ± 0.02, and combining these proteomic data with miRNA data further improved prediction accuracy to an R² of 0.70 ± 0.01, capturing a broader range of age-related physiological changes.