Endothelin is a hormone produced predominantly by endothelial cells that have been recognized to play a significant role in the development of several cardiovascular disease states. Its receptor ETA has been reported in a variety of tissues including placenta, uterus, testis, heart, adrenal gland, lung, kidney, ovary, skin, liver, bladder, large blood vessels, cerebellum, neurons, and meningioma tumor cells. In the vasculature, ETA receptors residing on smooth muscle cells mediate prolonged vasoconstriction. Furthermore, activation of the ETA mediates events that regulate mitogenesis, apoptosis, angiogenesis and metastasis in tumors. The Human EDNRA-FLAG stable cell lines-CHO expresses EDNRA cDNA that is identical to GenBank NM_001957.1 except for 1 mutation that results in a change in amino acid Leu to Val at position 322, which has been reported as a natural variant.