Consistent with this, preclinical data demonstrate that ibrutinib inhibits EGFR, HER2, and human epidermal growth factor receptor 3 (HER3) in breast cancer cell lines [3], and both EGFR (L858R) and EGFR (T790M) in mutant EGFR-expressing lung cancer cell lines [4]. Here, EGFR is linked to breast cancer.