The BCMC panel was used to characterise 53 PDTX samples which capture the diversity of breast cancers observed in the clinic37: 37.7% ER+Her2−, 11.3% Her2+, and 49.0% triple-negative; 3 of 5 PAM50 intrinsic subtypes; and 8 of 11 genomic driver-based IntClust subtypes (Fig. 2a and Supplementary Table 3). This evidence concerns the gene ERBB2 and breast cancer.