Heparin-binding protein which binds to FGF2, prevents binding of FGF2 to heparin and probably inhibits immobilization of FGF2 on extracellular matrix glycosaminoglycans, allowing its release and subsequent activation of FGFR signaling which leads to increased vascular permeability. Interacts with FGF2. In the adult, highly expressed in brain with lower levels in ovary. In the embryo, highest levels are found in the brain and spinal cord at 14 dpc and expression is almost completely restricted to the brain by 18 dpc. In the adult and postnatal brain, highly expressed in the orbitofrontal cortex where it is concentrated primarily in differentiated neurons. Expression is first detected at 10 dpc and reaches a peak at birth. After birth, levels decrease and remain constant throughout postnatal development. Mutants display a range of anxiety-related behaviors including reduced time spent in the central area of the open-field arena, reduced activity in lit areas of a light/dark transition test and prolonged latency to feeding in a novelty induced hypophagia test which assesses the drive to drink a sweetened milk solution. Belongs to the fibroblast growth factor-binding protein family.