TLX2 and pulmonary arterial hypertension: Gene expression of other Ca2+ extrusion mechanisms, Na/Ca2+ exchanger (NCX) and mitochondria calcium uniplex (MCU), did not change between groups (NCX: CTRL = 1 ± 0.11, PAH = 1.03 ± 0.15, PAH+RES = 0.86 ± 0.12; MCU: CTRL = 0.88 ± 0.13, PAH = 0.88 ± 0.13, PAH+RES = 0.96 ± 0.15 mRNA/HPRT).