MSH2 is an integral component of the DNA mismatch repair (MMR) system that functions to recognize aberrant structures and signals for the repair of single base mismatches or loops in replicated DNA. MSH2 has also been demonstrated to function as an anti-recombinase and may play a role in negatively regulating DNA repair. MSH2 can heterodimerize with MSH3 or MSH6. Mutations in MSH2 are linked to hereditary nonpolyposis colon cancer (HNPCC).