MLH-1 [G168-15] recognizes human and mouse MLH-1 (80-85 kDa). MLH-1 antibody and MSH2 are involved in the DNA mismatch repair (MMR) process. Microsatellite instability (MSI) is an alteration of microsatellite repeats during DNA replication and is a hallmark of the inactivation of the MMR genes. These defects in MMR have been related to human carcinogenesis. Immunostaining for MLH-1 and MSH2 may be useful to aid in identifying the most probable gene responsible for the MSI. Studies have shown that the expression level of MLH-1 may be a survival indicator.