In addition, in vitro and in vivo assessment of the sensitivity of cell lines containing an FGFR2 fusion to an FGFR inhibitor demonstrated sensitivity to treatment only in the fusion containing cells [53], [54], suggesting the presence of FGFR fusions may be a useful predictor of tumor response to FGFR inhibitors. The gene discussed is FGFR2; the disease is neoplasm.