To gain a complete overview of genetic alterations of all MLL3/4 COMPASS-like complex members, we mined publicly available pan-cancer sequencing data (www.cbioportal.org17 18) for truncating mutations, deep deletions and shallow deletions (online supplemental figure 1) and found that indeed the three catalytic subunits showed the highest alteration frequencies (KDM6A: 21%, KMT2D: 15%, KMT2C: 14%). This evidence concerns the gene KMT2C and cancer.