ERBB2 and breast cancer: In vitro proliferation assays showed that neratinib had various ranges of IG50 in the tested HER2+ breast cancer (IG50 = 0.28–1194 nM, median IG50 = 171 nM) and TNBC (IG50 = 185–5521 nM, median IG50 = 471 nM) cell lines (Figure 1A and Supplementary Figure S1A,B).