Our findings suggest that these TET2 and/or DNMT3A mutations may occur very early in the hematopoietic stem cells (HSC) before they give rise to the common lymphoid progenitors and common myeloid progenitors and propose a possible link between CH and development of AITL (Fiore et al., 2020a). The gene discussed is DNMT3A; the disease is angioimmunoblastic T-cell lymphoma.