Our findings suggest that chronic hypobaric hypoxia upregulates the expression of STIM1 in the distal intrapulmonary arteries which plays an important role in the hypoxia-induced PASMCs proliferation via SOC/Ca2+/NFAT pathway and may represent a novel therapeutic target for the prevention of hypoxia pulmonary hypertension. This evidence concerns the gene STIM1 and pulmonary hypertension.