The occurrence and development of CRC is a complex and multistage process involving the mutation of certain genes (APC, Kras, and P53) and the alteration of several signaling pathways (PI3K/AKT, Wnt/β-catenin, etc.), which are critically involved in the regulation of CRC cell growth, differentiation, angiogenesis, apoptosis, survival, and other biological processes. The gene discussed is APC; the disease is colorectal carcinoma.