Then, we further evaluated the prognostic value of the rest complement genes, whose mRNA expressions were not altered in HCC tissues, including C1S, C2, C3, C5, C8A, C8B, C8G, CFB, CFI, CFH, CFHR1, CFHR2, CFHR4, CFHR5, SERPING1, MASP1, MASP2, MBL2, C5AR2, C4BPA, C4BPB, VTN, CLU, CD59, CPN1, CR2, and ITGAM. The gene discussed is CR2; the disease is hepatocellular carcinoma.