NTRK1 and pulmonary arterial hypertension: Platelet-derived growth factor receptor, epidermal growth factor receptor and fibroblast growth factor signal through tyrosine kinase receptors in the pathological remodeling of the vascular bed and have been targeted by multiple chemical inhibitors including imatinib, nilotinib, gefitinib, sorafenib and sunitinib, for reversal of PAH progression.98, 99 Although a greater understanding of the pathogenesis of PAH and PAH-specific therapies has led to significant advances, the disease is still incurable and ultimately fatal.