FGF3 (fibroblast growth factor 3) is a growth factor that plays crucial roles in embryonic development and cancer progression. During development, FGF3 is essential for inner ear morphogenesis, hindbrain patterning, and tail formation 1. The protein functions through both classical paracrine signaling and unique intracrine mechanisms via alternative translation initiation sites 1. FGF3 activates fibroblast growth factor receptor (FGFR) signaling pathways and promotes cell proliferation and migration. In disease contexts, FGF3 mutations cause LAMM syndrome, characterized by hearing loss and inner ear malformations 1. FGF3 amplification occurs frequently in various cancers, including 41% of esophageal squamous carcinomas 2, hepatocellular carcinomas 3, and pancreatic adenocarcinomas 4. In cancer models, FGF3 promotes tumor growth through FGFR activation, which can be therapeutically targeted with small molecule inhibitors 2. The gene can be aberrantly activated by mutant transcription factors like KLF4K409Q in meningiomas 5. FGF3's expression is tightly regulated, as its dysregulation contributes to both congenital malformations and oncogenesis 1.