MUTYH and neoplasm: This sequence of events could explain the presence of an accentuated intra-epithelial lymphocytic infiltrate in MSI-high tumours.[14,32,33] In MAP carcinomas the disruption of the caretaker function of the BER machinery, mediated by MUTYH mutations, leads to the accumulation of G>T somatic mutations, at least early in tumourigenesis, which might evoke similar specific anti-tumour immune responses.