Our previous study of CpG methylation in iPSCs derived from two unrelated ICF1 patients (pG and pR) and their corresponding DNMT3B-corrected isogenic clones (cG13, cG50, and cR7, cR35) demonstrated that the majority of hypomethylated genome-wide CpGs in patient iPSCs were restored to normal levels following DNMT3B correction [24]. Here, DNMT3B is linked to immunodeficiency-centromeric instability-facial anomalies syndrome 1.