Although the expression of p18INK4C was partially affected by DNMT1, no significant upregulation of DNMT1 (P > 0.05, Figure S4c) or DNMT3B (P > 0.05, Figure S4d) mRNA levels was observed in 35 GC tissues (the same tissues used to detect DNMT3A expression) compared with non-tumor tissues. This evidence concerns the gene DNMT1 and neoplasm.