Increased expression of ERG causes myeloid leukemias in mice (Goldberg et al, 2013) and is associated with poor outcome in human AML (Tursky et al, 2015); genome‐wide loss of uSTAT5 binding may therefore contribute to the leukemogenic consequences of JAK/STAT activation by increasing access of ETS factors to their target genes. This evidence concerns the gene ERG and acute myeloid leukemia.