It is shown that colorectal cancer can develop via multiple genetic (APC, KRAS, TP53, BRAF, MMR) and epigenetic (MLH1) factors involving several distinct but intertwined pathways, such as Wnt signalling pathway, Myc signalling pathway, MAPK pathway, TGF-β pathway, and serrated neoplasia pathway. This evidence concerns the gene MLH1 and colorectal cancer.