ADAM23 and neoplasm: Although it has been reported that several tumour suppressor genes, such as p16 [31,32], E-cadherin [9,33] TIMP3 [34], DLC1 [35,36] and RUNX3 [37,38] silence GC and EC, only MINT25, RORA, GDNF, ADAM23, PRDM5, MLF1 showed frequent differential methylation in GC [39] which implies that different genetic and epigenetic mechanism are involved in the development and progression of these two tumour types.