In T-ALL, patients with DNMT3A mutations have been reported to have a significantly poorer overall survival compared to patients with wild-type DNMT3A [41], but it is not clear whether this finding is just a consequence of the fact that DNMT3A mutations are enriched in the more immature T-ALL subtypes, which show a poorer prognosis compared to mature T-ALL [26,42,47]. The gene discussed is DNMT3A; the disease is acute lymphoblastic leukemia.