PD173074 is a potent and selective inhibitor of fibroblast growth factor receptors (FGFRs), particularly FGFR1. It is widely used in research to study signaling pathways involved in cell proliferation, survival, and differentiation. Due to its ability to block FGFR-mediated signaling, it has become a valuable tool in cancer research, especially in models involving tumors driven by FGFR overexpression or mutations, such as certain types of breast, bladder, and lung cancers. In preclinical studies, PD173074 has demonstrated the ability to suppress tumor growth and induce apoptosis in FGFR-dependent cancer cell lines. It is also used to investigate angiogenesis, as FGFR signaling plays a key role in blood vessel formation. Researchers apply this compound in vitro and in vivo to validate FGFR as a therapeutic target and to explore mechanisms of drug resistance. Its selectivity makes it useful for distinguishing FGFR-related effects from those mediated by other tyrosine kinases, supporting the development of targeted cancer therapies. However, it remains a research compound and is not used clinically.