MLH1 and Lynch syndrome: The BRAF p. (V600E) mutation is detected in as many as 70% of tumors with loss of expression of PMS2 and MLH1 or show signs of MLH1 promoter methylation.6 The BRAF p. (V600E) mutation is rarely observed in tumors associated with Lynch syndrome.7 This being the case, evidence of the BRAF mutation can certainly show that the dMMR tumor has a sporadic origin.8 Both Polymerase Chain Reaction (PCR) based MSI detection and immunohistochemical (IHC) testing are methods of high sensitivity that are utilized in identifying a potentially defective MMR system.