ERBB2 and cancer: Principal component analysis (PCA) of the H3K27ac signal at HMEC mBEs suggested a correlation between cancer cell lines from the same cancer subtypes analyzed, i.e., luminal (Lum A and Lum B), HER2-amplified, and TN (including Basal (B) and Claudin Low (CL)), similar to the PCA of H3K27ac signal at all CREs (Fig. 4c).