MutL Homolog 1 or MLH1 is a protein involved in the mismatch-repair pathway. Anti-MLH1 Antibody is ready to be used for detection of MLH1. This protein has been commonly associated with hereditary non-polyposis colorectal cancer thus is a useful marker for the disease. MLH1 is optimized when paired in an IHC panel with MSH6，MSH2，and PMS2.
