MRC1 and colorectal carcinoma: CRC is classified into two categories: (i) the microsatellite instability-high (MSI-H) group, which has defects in the DNA mismatch repair (MMR) system and accounts for 15% of tumors, and (ii) the microsatellite stable (MSS) group, with proficient MMR proteins, which accounts for the remaining 85% of tumors [56,57,58].