SRC and pulmonary arterial hypertension: c-Src plays an important role in activation of MAPKs associated with cell growth, apoptosis, and collagen deposition.30 Previous studies demonstrated that c-Src is both a redox-sensitive downstream target of Nox and an upstream signaling molecule for Nox activation31 and can increase protein abundance subunits and adaptor proteins required for regulation of Nox activity.16 Importantly, PP2 reduced serotonin-stimulated ROS formation exclusively in PAH-hPASMCs, suggesting a role for c-Src in serotonin-mediated Nox activation in PAH.