DNMT1（DNA (cytosine-5-)-methyltransferase 1），癌症关联基因，基因ID：1786，这个基因编码一种将甲基转移到基因组DNA的胞嘧啶核苷酸的酶。这种蛋白是在DNA复制后维持甲基化模式的主要酶，并表现出对半甲基化DNA的偏好。DNA甲基化是哺乳动物表观遗传基因调控的重要组成部分。异常甲基化模式在人类肿瘤中发现并与发育异常有关。这种基因的变异与小脑共济失调、耳聋和嗜睡、神经病变、遗传感觉、类型IE有关。选择性剪接导致多种转录变异。This gene encodes an enzyme that transfers methyl groups to cytosine nucleotides of genomic DNA. This protein is the major enzyme responsible for maintaining methylation patterns following DNA replication and shows a preference for hemi-methylated DNA. Methylation of DNA is an important component of mammalian epigenetic gene regulation. Aberrant methylation patterns are found in human tumors and associated with developmental abnormalities. Variation in this gene has been associated with cerebellar ataxia， deafness， and narcolepsy， and neuropathy， hereditary sensory， type IE. Alternative splicing results in multiple transcript variants.关联癌症：胃腺癌，卵巢癌。关联化疗药物：Decitabine。