Abstract: Novel nucleic acids, polypeptide sequences, and nucleic acid regulators thereof, have been identified which code for a fibroblast growth factor (FGF), preferably FGF-20 or FGF-23, a class of polypeptides involved in development, differentiation, and morphogenesis, e.g., in cell-cell signalling and cell proliferation. An FGF of the present invention, fragments thereof, and derivatives thereof, have one or more of the following biological activities, e.g., promoting wound healing; promoting neuronal survival; stimulating cell proliferation, e.g., proliferation of stem cells, fibroblasts, neurons, glia, oligodendrocytes, Schwann cells, or progenitors thereof; modulating differentiation of cells; inducing embryonic development; stimulating neurite outgrowth; enhancing recovery from nerve or neuronal damage; stimulating myelination; stimulating angiogenesis; receptor binding activity; modulating tumorigenesis, etc.