RUNX1 and breast cancer: We also identified recurrent mutations in recently reported genes in BC, such as UBE2A13,14 and SETD1B13, as well as in previously unreported genes, such as KLC2 and NBEAL2. Deep amplicon sequencing of these mutations at a mean depth of ×2589 in paired CP and BC samples revealed that ASXL1 mutations were already present in the CP samples, whereas other major drivers, including RUNX1, ABL1, and TP53 mutations were initially absent in CP and emerged during progression to BC (Fig. 1d).