C8A and cancer: C8A is a key constituent of the membrane attack complex that regulates the pore formation in target cells and regulates the underlying innate and adaptive immune responses.27 The high C8a expression was previously reported in CRC metastasis compared to the primary tumor which supports its potential role in CRC progression.34 Moreover, the C8A level was also enhanced in patients with cancer-associated inflammation, suggesting that this complement protein is linked to the systemic inflammation promoted by CRC to facilitate metastasis from the primary tumor.