NRP1 and pulmonary arterial hypertension: Pharmacological inhibition of NRP1 with EG00229 or siRNA-mediated knockdown of NRP1 in PAH-PAECs significantly downregulated the expression of key metabolic genes, including PKM2 (pyruvate kinase M2, a rate-limiting glycolytic enzyme), PFK1 (phosphofructokinase-1, a key regulator of glycolysis), LDHA (lactate dehydrogenase A, involved in anaerobic glycolysis), and GLUT1 (glucose transporter 1, mediating basal glucose uptake) (Fig. 4H).