Adenomatous polyposis coli (APC) is a tumor suppressor gene that plays a crucial role in regulating cell growth and maintaining genomic stability, with mutations in this gene leading to conditions like familial adenomatous polyposis (FAP) and increased colorectal cancer risk. The APC protein is involved in the Wnt signaling pathway, where it helps control the degradation of β-catenin, a protein that, when accumulated, can cause uncontrolled cell division and tumor development.