Mice with conditional Hdac1 alleles but wild type for Dot1L (Lck‐Cre;Hdac1f/f) developed thymic lymphomas for which they had to be sacrificed, with a median latency of 21 weeks and an incidence of 86% during the 40‐week length of the experiment, comparable to what was observed before (Fig 3C and D) (Heideman et al, 2013). The gene discussed is DOT1L; the disease is thymus lymphoma.