Similarly, we found, in renal carcinomas of a clear cell type, that virtually all cancers expressed erythropoietin [106], which indicates that the erythropoietin cell is the cell of origin and which could also explain the role of hypoxia and hypoxia-inducible transcription factors (HIF) in clear-cell renal cancer [107]. The gene discussed is EPO; the disease is clear cell renal carcinoma.