Targeted-capture sequencing of additional LCM samples for mutations in the main trunk confirmed that AKT1-mutated lobules derived from the MRCA widely expanded over the 65 mm area, showing a variety of histologies, including proliferative and non-proliferative as well as DCIS lesions (Extended Data Figs. 3c and, 5d). This evidence concerns the gene AKT1 and ductal breast carcinoma in situ.