BMPR2 and pulmonary arterial hypertension: In vitro and in vivo studies demonstrate the efficacy of FK506 (tacrolimus) and Seralutinib in improving PAH by increasing the expression of BMPR2 and activating its downstream signaling.388,389 Clinical trials have confirmed the safety of FK506 and Seralutinib in PAH patients, with an increase in BMPR2 expression observed.