The evolving discipline of molecular pathological epidemiology (MPE) offers a powerful approach to explain the interpersonal susceptibility to carcinogenesis and to clarify the role of microbial variation and dysbiosis in the development and progression of tumour anatomical sub-sites within the colorectum and by tumour molecular sub-type features (e.g., inherited MMR mutations, somatic mutations such as in the KRAS, APC, BRAF and PIK3CA genes, microsatellite instability, epigenetic modifications) (62). This evidence concerns the gene KRAS and neoplasm.