The results of several linkage and association studies of HTN and SBP have suggested candidate genes, including: angiotensinogen (AGT) [7], tumor necrosis factor receptor-2 (TNFR2) [8], endothelin-converting enzyme-1 (ECE1) [9], angiotensin receptor (AGTR1), beta-3 subunit of guanine nucleotide-binding protein (GNB3) [10], and prostaglandin I2 synthase (PTGIS) [11]. This evidence concerns the gene PTGIS and hypertensive disorder.