The CRC showing loss of MLH1/PMS2 protein expression from Pat_301 had two somatic mutations in MLH1 (c.1813G>T p.(Glu605Ter) and c.1816G>T p.(Gly606Ter)) and no evidence of tumour MLH1 promoter hypermethylation. Here, PMS2 is linked to colorectal carcinoma.