During the developmental phase of PAH, macrophage-derived caspase-8 plays a pathogenic role in peripulmonary vascular inflammation by promoting inflammatory cell infiltration and proliferation of pulmonary artery smooth muscle cells through the NACHT, LRR, and PYD domains-containing protein 3 (NLRP3)/interleukin (IL)-1β signaling activation.48 Here, NLRP3 is linked to pulmonary arterial hypertension.