The recent studies on MMR protein expression in prostate tumours revealed that approximately 10% of advanced/metastatic prostate tumours have an underlying somatic and/or germline inactivation of genes in the MMR family (mutS homologue 2 (MSH2), MSH6, mutL homologue 1 (MLH1) or PMS2) [13,15]. This evidence concerns the gene PMS2 and prostate neoplasm.