Yet multiple lines of evidence suggest that HIF1α functions as a tumor suppressor, which is inactivated in a high percentage of ccRCCs (Shen et al., 2011); in contrast, HIF1α is believed to promote the tumorigenic properties of many other tumors, making it difficult to understand how HIF1α might differentially function in tumorigenesis of different cell types. The gene discussed is HIF1A; the disease is neoplasm.