Scientists at NIDDK have developed a fibroblast growth factor receptor 1 (Fgfr1) conditional knock out mouse. Fgfr1 is a member of the Fgfr family of transmembrane protein receptors with intrinsic tyrosine kinase activity. Fgfr1 is important in multiple biological processes, including mesoderm induction and patterning, cell growth and migration, organ formation and bone growth. Fgfr1 is highly expressed in central nervous system tissues and plays a critical role in proliferation, migration, and survival of neurons and glial cells. Additionally, overexpression of Fgfr1 has been associated with mammary gland transformation and may be crucial for the development of some cancers. The Fgfr1 conditional knockout mouse can be used to study development and biological processes in a variety of tissues and can provide information on signaling pathways that interact with Fgfr1 to induce genes important for critical cellular events, such as proliferation, differentiation, adhesion, movement, survival, and transformation.