DNMT3B and cervical carcinoma: However, colon cancer cells depleted of folate alone are reported to show a decrease in DNMT3a [32, 56], and Poomipark et al. reported a decrease in DNMT3a and DNMT3b in a folate and methionine-depleted cervical cancer cell line C4II [22], adding to the evident inconsistency of response to single or multiple methyl donor depletion in different experimental systems.