DNMT1 and melanoma: In order to induce pharmacological DNMT inhibition and DNA demethylation, the melanoma cell lines C918, IGR1, MeWo, SkMel13 and SkMel19 were treated for four consecutive days with 5 μM of the DNA-methyltransferase (DNMT)-inhibiting agent 5-aza2′deoxycytidine (vs. mock treatment 0 μM Aza).