Bearing in mind the importance of inflammation for the formation and progression of colorectal cancer [81,82,83,84,85], it is possible that C3, by influencing the expression of inflammatory molecules TNF-α, pro-IL-β, ICAM-1, and VCAM-1 in the tissue of the primary tumor, reduces tumor growth and progression, and also stimulates the apoptosis of tumor cells in vivo. This evidence concerns the gene ICAM1 and colorectal cancer.