APC and neoplasm: In the absence of Wnt stimulation, β-catenin is targeted for proteasomal degradation by the destruction complex, which includes the two tumour suppressors: Axin and Adenomatous polyposis coli (APC), and two kinases: casein kinase 1α (CK1α) and glycogen synthase kinase 3 (GSK3)3, 4, 5, 6.