The upregulation of C2, C3, C4, and factor B but not C5 and the complement factors (C6-C9) required for generation of the membrane attack complex (MAC), which is an important effector protein, is consistent with other literature describing complement factor expression in colorectal carcinoma cell lines stimulated with various cytokines [46, 47]. This evidence concerns the gene C2 and colorectal carcinoma.