Immunohistochemistry using antibodies against HIF-1α to analyze primary tumor biopsies has demonstrated that increased HIF-1α expression is associated with increased patient mortality in bladder, brain, breast, cervical, colorectal, endometrial, esophageal, gastric, head/neck/ oropharyngeal, hepatocellular, lung, ovarian, and pancreatic cancer as well as acute leukemias and melanoma.9,10 In many cancers, HIF-1α expression is observed in a peri-necrotic pattern, representing the viable cells that are furthest away from a blood vessel and therefore the most hypoxic. This evidence concerns the gene HIF1A and cancer.