Four consensus molecular subtypes (CMSs) have been defined, helping to comprehend biological complexity and heterogeneity of CRC: CMS1, which is hypermutated and strongly immunogenic; CMS2, which shows chromosomal instability and WNT/MYC activation; CMS3, which shows metabolic dysregulation and KRAS mutation; and CMS4, which is characterized by CpG hypermethylation, TGF-β activation, stromal invasion, and angiogenesis [5]. The gene discussed is KRAS; the disease is colorectal carcinoma.