FGFR3 and systemic sclerosis: FGF9 was shown to bind FGFR3 and activate dermal fibroblasts from SSc skin, leading to the downstream stimulation of AKT, p38, extracellular signal-regulated kinase (ERK), and calcium/calmodulin-dependent protein kinase 2 (CAMK2) and promoting cyclic adenosine 3′,5′-monophosphate response element binding protein (CREB) activation, which induced the expression of profibrotic mediators [50].