Probably involved in the repair of mismatches in DNA. Heterodimer of MLH1 and MLH3. Interacts with MTMR15/FAN1. Ubiquitous. The disease is caused by variants affecting the gene represented in this entry. The disease is caused by variants affecting the gene represented in this entry. Belongs to the DNA mismatch repair MutL/HexB family. Contaminating sequence. Sequence of unknown origin in the N-terminal part.