Treatment of acute lymphoblastic leukemia cell lines with the non‐selective HDAC inhibitor Panobinostat showed changes in H2Bub, with decreased H2Bub in MLL‐r leukemia lines and increased H2Bub in non‐MLL‐r leukemia lines, suggesting context‐dependent mechanisms (Garrido Castro et al, 2018). This evidence concerns the gene HDAC9 and leukemia.