MLH1 is a gene that provides instructions for making a protein involved in the repair of DNA. This protein plays a crucial role in maintaining the stability of a cell's genetic information by correcting errors that occur during DNA replication. Proper functioning of MLH1 is essential for preventing mutations that could lead to various diseases, including cancer. Mutations in the MLH1 gene can disrupt its normal function, increasing the risk of certain types of cancer, particularly Lynch syndrome, which is associated with colorectal and endometrial cancers. Genetic testing for MLH1 mutations can help identify individuals at higher risk, allowing for early monitoring and intervention.