Paraffin-embedded HCC and the corresponding non-tumour adjacent tissue were investigated for MSI of all those samples showing promoter methylation in one of the tested MMR genes using two mononucleotide markers, BAT25 (a poly(A) tract occurring in intron 16 of c-kit [18]) and BAT26 (a poly(A) tract localized in the fifth intron of hMSH2 [19]). The gene discussed is KIT; the disease is hepatocellular carcinoma.