FGFR1 and breast cancer: To evaluate the relative effect of the FGFR inhibitors we first used two cell lines derived from solid tumors, the H1581 large-cell lung carcinoma cell line and the human MDA-MB-134VI breast cancer cell line, both of which overexpress FGFR1 and have been shown to be sensitive to at least one of these FGFR inhibitors [8, 9].