FGFR1 and breast carcinoma: In this study, we have used both FGFR1-dependent murine leukemia cell lines carrying different chimeric FGFR1 fusion kinases as well as FGFR1-dependent lung and breast cancer lines with amplification of FGFR1, to compare the ability of 5 different pan-FGFR inhibitors to suppress FGFR1 activation and subsequent leukemogenesis, We show that BGJ398 is the most efficient inhibitor based on in vitro cell growth inhibition and apoptosis assays.