FGF-10 (Fibroblast Growth Factor 10) is a heparin binding glycoprotein in the subgroup of FGFs that also includes FGF-3, -7, and -22. FGF-10 is secreted by mesenchymal cells and associates with extracellular FGF-BP. It preferentially binds and activates epithelial cell FGF R2 (IIIb) and interacts more weakly with FGF R1 (IIIb). The mitogenic and chemotactic properties of FGF-10 are critical in limb bud initiation, palate development, branching morphogenesis and directional outgrowth of lung buds, formation of the otic vesicle and chochlea, adipogenesis, and the development of prostate, mammary, lacrimal, and submandibular salivary glands. The expression and function of FGF-10 are negatively regulated by Shh and BMP-4 in the developing lung. Overlapping expression patterns and activities with FGF-3, -7, and -8 suggest at least a partial redundancy in FGF-10 biology. FGF-10 induced signaling through FGF R2 (IIIb) also contributes to the progression of pancreatic cancer.