APC and adenoma: In this context, β-catenin could be active in the nucleus below the limit of detection by immunofluorescence, but it is also possible that elevated β-catenin caused by APC loss is insufficient to initiate hyperproliferation and microadenoma formation and that other pro-proliferative stimuli, including mTORC1 activation [80,94,105,139,142,143,144,145,146,160], could contribute to early adenoma formation.