Further exploration with different cohorts (a total of 8 patients with the two malignancies) demonstrated that 2 out of 8 patients had a germline missense or promotor variant of MLH1 and four out of 10 tumour specimens revealed heterogeneous immunohistochemistry staining in any of the four mismatch repair proteins: MLH1, PMS2, MSH2 and MSH6. Here, PMS2 is linked to neoplasm.