We discovered that the positive rates of DNMT1, DNMT3a, and DNMT3b expression in GC tissues were 78.4% (229/292), 78.4% (229/292), and 79.8% (233/292), respectively, and they were significantly higher than those of three PCHNTs (19.2%, 18.2%, and 14.4%) and non-cancer control tissues (8.8%, 7.2%, and 6.4%). The gene discussed is DNMT3A; the disease is cancer.