APC and colorectal carcinoma: In CRC etiology, the decisive role is attributed to the genetic changes (especially mutations of tumor suppressor genes and/or proto-oncogenes) occurring in different stages of carcinogenesis (e.g., mutation of the Adenomatous Polyposis Coli (APC) gene during the initiation, and Kirsten Rat Sarcoma Virus (KRAS, K-Ras) gene mutation during the progression of the tumorigenesis) [20].