KMT2A and leukemia: Selective inhibitors of DOT1L with cellular activity (EPZ004777 and SGC0946) [14, 15] have been described, and a further optimized inhibitor (EPZ-5676) [16] has even advanced to clinical trials in MLL-rearranged leukemia, where fusion proteins of MLL with a variety of partners recruit DOT1L to a set of genes (e.