To determine whether hypoxia contributes to the generation of Ang II in tumor cells, we first measured the Ang II levels in the supernatant of in vitro cultured tumor cells from CNE1, CNE2 and 5–8F nasopharyngeal carcinoma cells and MDA-MB-231 breast cancer cells, both of which display predominant hypoxia in their solid tumors17, 18. The gene discussed is AGT; the disease is breast carcinoma.