IL1R1 and pulmonary arterial hypertension: The three upregulated candidate genes are WASF1, ARHGEF1 and RB1 and the seven downregulated candidate genes are IL1R1, RHOB, DAPK1, TNFAIP6, PKN1, PLOD2, and MYOF. WASF1, ARHGEF1, and RB1 were upregulated significantly in hypoxia with Sugen-induced PAH, while IL1R1, DAPK1, and TNFA1P6 were upregulated significantly in hypoxia with Sugen-induced PAH.