APC (Adenomatous Polyposis Coli protein) is a multifunctional tumor suppressor protein crucial in the Wnt/β-catenin signaling pathway, regulating cell proliferation and differentiation. Structurally, it includes multiple binding domains, such as the ARM repeat domain, interacting with proteins like β-catenin. It primarily localizes in the cytoplasm and nucleus, participating in the degradation of β-catenin. Members of the APC family exhibit specificity in expression across different tissues, playing a significant role in cell cycle control and cell adhesion. Mutations in the APC gene frequently occur in diseases such as colorectal cancer, leading to abnormal activation of the Wnt signaling pathway and promoting tumor formation.