Higher PTK6 transcript expression in patient tumors is associated with adverse outcomes.19 In fact, increased expression of PTK6 in MCF-10A breast epithelial cells was sufficient to confer resistance to the growth inhibitory effects of treatment with lapatinib, a clinically used small molecule inhibitor of HER1/2 kinases.24 Furthermore, we reported that PTK6 downregulation impaired the growth of several lapatinib-resistant HER2+ breast cancer cell lines and induced apoptosis by enhancing Bim expression.25 Here, PTK6 is linked to breast cancer.