Diagnostic performance of the three molecular assays was evaluated in 49 selected tumor samples (flowchart Fig. 1): colorectal (CRC, n = 28) and uterine corpus endometrial carcinoma (UCEC, n = 21) were classified as dMMR or pMMR using immunohistochemical detection of MLH1, PMS2, MSH6 and MLH1 expression as reference technique, and subjected to blinded analysis of MSI status by the three molecular techniques. Here, MLH1 is linked to colorectal carcinoma.