IFNG and idiopathic pulmonary arterial hypertension: Both IFN-α and IFN-γ levels were significantly elevated in PH patients compared with controls (P < 0.05 for both), with IFN-α showing stronger predictive value across multiple PH subgroups (P < 0.05 for all), particularly in patients with Group 4 PH and idiopathic pulmonary arterial hypertension (IPAH).