DNMT1 and glioblastoma: Firstly, we performed a colorimetric assay to quantify DNMT activity in nuclear extracts of GBM cells treated for 24 h with IPA, N6-BA, 5-Aza-2′-deoxycytidine (5-AZA-dC or decitabine), or a combination of IPA and 5-Aza-dC.