Increases in Drp1 or decreases in fusion mediators result in mitochondrial fragmentation in both PASMC and pulmonary artery adventitial fibroblasts in PAH (Marsboom et al., 2012; Ryan et al., 2013; Plecita-Hlavata et al., 2016; Chen et al., 2018). Here, DNM1L is linked to pulmonary arterial hypertension.