The microarray datasets retrieved from the lung tissues of patients with PAH were investigated, and 38 mutual core DEGs (SCARNA4, GALNT1, CCDC186, EEA1, SMC4, GCC2, ZNF721, EPRS, RAD50, POSTN, DNTTIP2, RAMP2, HSP90AA1, ZNF845, HSPD1, NEXN, CFH, ZNF267, HSP90AA6P, CD163, HIGD1B, PI15, SNORD20, ANGPT2, S100A3, TDO2, SOSTDC1, ANLN, TSHZ2, SLC7A11, MS4A15, HSPH1, DKC1, TTN, VSIG1, SPP1, RNU5D-1, and MMP8) were detected between the two datasets. Here, TDO2 is linked to pulmonary arterial hypertension.