growth factor signaling pathway fibroblast growth factor signaling pathway FGF signaling pathway PW:0000328 Signaling by FGFR The family of fibroblast growth factors (FGF) comprises 22 ligands classified into seven phylogenetic subfamilies and three groups by mode of action: the intracellular intracrine and the extracellular paracrine or canonical and endocrine or hormone-like groups. The paracrine subfamilies signal via the fibroblast growth factor receptors (FGFR), receptor tyrosine kinases (RTK). The endocrine subfamily is FGFR-dependent but the affinity towards the receptors is low and it relies on the Klotho family of transmembrane proteins. The intracrine subfamily is FGFR-independent. Overall, the pathway plays important roles during embryonic and postnatal development, neuromodulation, mineral metabolism and homeostasis. Deregulation of the pathway has been associated with neoplastic and metabolic diseases. fibroblast growth factor receptor signaling pathway pathway