MLH1 and colorectal carcinoma: In another study, the objective of which was to assess MMR abnormalities in the tumors of Mexican CRC patients under 50 years old, CRC paraffin-embedded tissues of 47 patients with available demographic/clinical data were studied by immunohistochemistry (IHC) for MLH1/MSH2, qPCR with specific probes/sequencing for the BRAF V600E mutation, and conventional PCR (5 markers) for MSI analysis.