APC and colorectal neoplasm: Since the APC/Wnt/β-catenin pathway is known to play a major role in colorectal carcinogenesis and since both CK1 isoforms play regulatory roles in Wnt signaling it can be speculated that overexpression of CK1α and δ leads to a Wnt/β-catenin-dependent malignant phenotype of colorectal tumor cells [15, 22, 23].