MSI CRCs are mostly enriched for the epigenetic inactivation of the MLH1 gene, have a CIMP-positive and SCNA-low phenotype, show high frequency of the BRAFV600E mutation and a low frequency of APC and TP53 mutations, and are characterized by their occurrence in females at a late age and in the proximal colon, with poor tumor differentiation and mucinous/signet-ring cell histology. The gene discussed is TP53; the disease is neoplasm.