In vitro and in vivo experiments showed that Jag2 acts as an upstream regulator of NOX2 and activates the NOX2/ROS pathway under hypoxic conditions, promoting the formation of the vascular inflammatory microenvironment, enhancing PASMC proliferation and migration, and aggravating vascular remodeling in hypoxic PAH. The gene discussed is JAG2; the disease is pulmonary arterial hypertension.