ATOH1 and colorectal carcinoma: Owing to the fact that our promoter luciferase assays did not yield conclusive results, we went on to examine alternate pathways downstream of β-catenin that may regulate MUC4. We focused on Hath1 because this well-established tumor suppressor gene in CRC has been shown to be repressed by β-catenin and regulate MUC2 in CRC [14].