Exposure of gastric cancer cell lines (BGC-823, HGC-27, and SGC-7901) to hypoxia (1% O2) or chemical hypoxia induced by CoCl2 markedly increases CD73 (ecto-5′-nucleotidase) expression through HIF-1α-dependent transcriptional activation (Table 1) [19]. The gene discussed is HIF1A; the disease is gastric cancer.