TET2 and DNMT3A have opposite functions and their effect on methylation dysregulation is likely complex and understanding target genes affected by methylation alterations due to single or combined TET2 and DNMT3A mutations is important and it will be critical to elucidate their individual and cooperative role in AITL tumorigenesis. The gene discussed is TET2; the disease is angioimmunoblastic T-cell lymphoma.