DNMT1 and Immunodeficiency: A major concern with the use of DNMT inhibitors is their potential to induce genomic rearrangements, traditionally attributed to global demethylation based on cytogenetic observations made in the immunodeficiency, centromeric region instability, facial anomalies (ICF) syndrome [11] but also attributable to the formation of DNMT1 adducts in cells treated by 5-aza-CdR [12].