FGFR1 (Fibroblast Growth Factor Receptor 1) is an important isoform of the receptor tyrosine kinase family encoded by the FGFR1 gene, acting as a core transmembrane receptor of the FGF signaling pathway. Ubiquitously expressed in embryonic and adult tissues, FGFR1 binds fibroblast growth factors (FGFs) to activate intracellular tyrosine kinase domains and trigger downstream signaling cascades including Ras/MAPK and PI3K/Akt, regulating cell proliferation, differentiation, migration, angiogenesis, embryonic development and tissue repair. Aberrant FGFR1 amplification, mutation or sustained activation causes excessive pathway activation, driving tumor proliferation, invasion, angiogenesis, fibrosis and developmental malformations. It is a core therapeutic target for multiple solid tumors and proliferative diseases.