Our results showed that silencing AID depleted DNMT1 with the concomitant induction of hypermethylated TSGs, such as p21 and Rassf1a, suggesting that differential gene expression in AID+/+ and AID-/- cells may be attributed to DNMT1 levels in cells, in which the methylation status of tumor suppressive genes was altered. The gene discussed is RASSF1; the disease is neoplasm.