EGFR and breast cancer: This unfortunate and therapeutically limiting side effect may be inherent in EGFR-targeting TKIs, as all three generations of TKIs have significantly or completely inhibited the autophosphorylation of WT EGFR in both melanoma WM983B (Figure 1) and WM983A (Figure S1A), breast cancer MCF-7 (Figure S1B), and human non-small cell lung carcinoma H1299 (Figure S1C) cell lines cultured in complete growth media, which most likely mimic human physiological conditions.