One recent in vitro study demonstrated that tamoxifen- and fulvestrant-resistant breast cancer cell lines were sensitive to treatment with lapatinib or afatinib (a second-generation anilinoquinazoline that irreversibly binds to the intracellular tyrosine kinase domains of EGFR, HER2, and HER4 receptors), and gradual reactivation of ERα sensitivity was observed with lapatinib therapy34. Here, ESR1 is linked to breast carcinoma.