DNMT1 and malignant colon neoplasm: Reports of effects of folate depletion on DNMT1 expression in cultured cells are inconsistent; Stempak et al., [56] reported a down-regulation in mouse fibroblasts and human colon cancer cells, whilst Hayashi et al. [32] observed an up-regulation in response to folate depletion of the same human colon cancer cells.