LEPR and pulmonary arterial hypertension: We, therefore, sought to understand the role of leptin and leptin receptors in free fatty acid uptake in PAH-RV cardiomyocytes using cultured cardiomyocytes (H9C2) with two different BMPR2 mutations: M1, a cytoplasmic tail domain mutation, and M2, a kinase domain mutation (Figure 4).