It has been demonstrated previously that PTGIS can inhibit cell growth in lung to alleviate pulmonary hypertension (Tuder et al., 1999) and overexpression of PTGIS in human embryonic kidney epithelial 293 (HEK-293) cell line can induce cell death (Hatae et al., 2001). This evidence concerns the gene PTGIS and pulmonary arterial hypertension.