In KU539, the DCIS clone in no. 5 had two driver mutations in PIK3CA and CBFB in addition to a GATA3 mutation and der(1;16), although the invasive cancer clone (in no. 4) in the same clade had no additional driver alterations (Extended Data Fig. 5a). This evidence concerns the gene GATA3 and ductal breast carcinoma in situ.