KRAS and colorectal carcinoma: Depending on the genetic expression, CRC can be classified into four different consensus molecular subtypes (CMSs): CMS1, which is associated with immune infiltration; CM2S (classical CRC), which is characterized by chromosomal instability, epithelial signature, and activation of WNT pathway; CMS3, which presents a strong epithelial composition, modification of different processes associated with metabolism and KRAS mutations; and CMS4, which shows a more mesenchymal signature, activation of EMT-related genes, remodeling of extracellular matrix, and activation of TGF-β signaling [115].