MSH6 and neoplasm: With respect to the expression of the four ‘classical’ MMR proteins, all 46 MSI‐H tumours in this study population showed loss of expression of two or one of the MMR proteins (combined loss of MLH1/PMS2: n = 43; combined loss of MSH2/MSH6 n = 1; isolated loss of MSH6: n = 1; isolated loss of PMS2: n = 1).