Validation across independent datasets (GSE117261 and GSE84395) generally supported their potential, although discrepancies surfaced in GSE33463, particularly evident in the varied expression of KEAP1, PRDX1, and TNFAIP3. Among the DE-FRGs, we suggest that PRDX1 is linked to endothelial dysfunction and that TNFAIP3 is associated with immune responses, serving as a potential diagnostic marker for IPAH. This evidence concerns the gene KEAP1 and endothelial dysfunction.