EGFR and breast cancer: Moreover, in accordance with landmark clinical studies suggesting that HER2 inhibition may be beneficial in the adjuvant setting for HER2 nonamplified BC patients [80,81], Lee and colleagues documented that the pharmacologic inhibition of EGFR, HER2, or both receptors reduced BCSC survival and self-renewal both in vitro and in vivo and increased BCSC sensitivity to ionizing radiation also in HER2-low BC [82].