NRAS and colorectal carcinoma: Recent advances in the molecular classification of CRCs are highly clinically relevant, with more widespread adoption of next-generation sequencing and All-RAS testing to identify additional isoforms of KRAS and NRAS. CRC tumors were previously classified mainly into several molecular subtypes that included chromosomal instability, microsatellite instability, and DNA hypermethylation or CpG island methylator phenotype (CIMP) [49].