KMT2D and cancer: Recent studies have provided evidence for a role for MLL2 and MLL3 in histone H3K4 methylation at enhancers (Hu et al. 2013; Lee et al. 2013; Cheng et al. 2014), and it has thus been suggested that their role in cancer might be explained through deregulated expression of oncogenes and tumor suppressors (Herz et al. 2014).