SMURF1 and pulmonary arterial hypertension: Some authors haveproposed that SMAD-specific E3 ubiquitin protein ligase 1 (SMURF1) could be a keyregulator for miR-140-5p targets and bone morphogenetic protein (BMP) signaling.This indicates that reduced miR-140-5p expression is associated to increasedpulmonary vascular SMURF1 protein expression and reduced BMP signaling in patientswith PAH and that inhibition of SMURF1 provides a potential mechanism by which BMPsignaling may be augmented for therapeutic benefit (77).