The results showed that higher mRNA expressions of 32 genes of the complements, namely C1R, C1S, C2, C3, C5, C6, C7, C8A, C8B, C8G, CFB, CFI, CFP, CFH, CFHR1, CFHR2, CFHR3, CFHR4, CFHR5, SERPING1, MASP2, MASP1, MBL2, C4BPA, C4BPB, VTN, CLU, CD59, CPN1, and CR2 were associated with longer OS in HCC patients while the higher mRNA expression of C5AR2 and ITGAM was associated with shorter OS in HCC patients (Table 3). The gene discussed is C5AR2; the disease is hepatocellular carcinoma.