The PMS2 gene produces the DNA repair proteins neededfor mismatch repair. Due to microsatellite instability (MSI),which is brought on by an accumulation of DNA replicationerrors in proliferating cells, carriers of mutations in themismatch repair gene have a high lifetime risk ofdeveloping endometrial cancer as well as Hereditary Non-Polyposis Colon Cancer (HNPCC) and several other cancers.In addition to MLH1, MSH2, and MSH6, PMS2 aids in thediagnosis of MSI.Compared to tumours with no MSI or high-level MSI,tumours with low-level MSI exhibit undesirable pathogenicfeatures.