The significant difference in TCR diversity of patients with ICF1 and ICF2 suggests that ZBTB24 and DNMT3B might bind to different partners in the regulation of DNA methylation and lymphocyte epigenetic modification, contrary to the previous speculation of ZBTB24 and DNMT3B forming a complex during regulation of DNA methylation. This evidence concerns the gene DNMT3B and immunodeficiency-centromeric instability-facial anomalies syndrome 1.