Ting et al [9] found that hypermethylation of CDKN2A, SFPR1, GATA4 and GATA5 were still maintained in HCT116 colorectal cancer cells after transiently or stably depleted of DNMT1, and suggested that DNMT1 might not play the dominant effect which caused hypermethylation of CpG islands in tumor suppressor genes. The gene discussed is GATA5; the disease is colorectal cancer.