BI-1347 is a potent and selective inhibitor of the fibroblast growth factor receptor (FGFR) family, particularly FGFR1. It is primarily used in research settings to study signaling pathways involved in cell proliferation, survival, and differentiation. Due to its ability to block aberrant FGFR signaling, it has shown promise in preclinical studies for the treatment of cancers driven by FGFR gene amplifications, mutations, or fusions, such as certain types of bladder, lung, and breast cancers. The compound is employed in in vitro and in vivo models to evaluate tumor response and mechanism of resistance to FGFR inhibition. Its high selectivity helps minimize off-target effects, making it a valuable tool for validating FGFR as a therapeutic target. BI-1347 is also used in combination studies with other anticancer agents to assess synergistic effects and improve therapeutic outcomes in resistant tumor types.