Klinger et al. (214) studied a Sugen5416/hypoxia-induced PAH rat model and showed that MSC-EVs reduced macrophage recruitment, promoted a shift from an inflammatory to a reparative macrophage phenotype, promoted angiogenesis, and reduced the expression of inflammatory cytokines such as IL-6, macrophage inflammatory protein 2 (MIP-2) and TNF-α. Here, IL6 is linked to pulmonary arterial hypertension.