Scheme (A, above) for the development of resistance to ponatinib where, after 2 years of selection, four different cell lines overexpressing FGFR1 kinase were developed which are resistant to >1000 nM (below). At a 100 nM concentration, which significantly inhibits proliferation in the parental cells, the resistant cells still show active proliferation (B). Although resistance was induced following exposure to ponatinib, the same cells are also resistant to other FGFR1 inhibitors; TKI258 (TKI), AZD4547 (AZD), E3810 (E). PD173074 (PD) and BGJ398 (BGJ) at the concentrations (nM) indicated in (C).