Histone H3 methyltransferases with mutations in more than 2% of ER-negative/HER2-negative cases included KMT2C, KMT2D and SETD2 (8.3%, 7.6% and 3.4%, respectively), with no significant differences between claudin-low and basal-like breast cancers (not shown). Here, KMT2C is linked to breast cancer.