BRAF and colorectal carcinoma: CDX2 is a tumor suppressor in the adult colon, and loss of CDX2 expression is associated with advanced stages of CRC, poor differentiation, BRAF mutation, and MSI (Olsen et al., 2014), as well as the CMS1 and CMS4 subtypes (Pilati et al., 2017; Trinh et al., 2017).