EPO and hepatocellular carcinoma: In addition, the level of Tyr-593-phosphorylated (activated) pro-apoptotic erythropoietin-producing human hepatocellular carcinoma receptor tyrosine kinase A2 (EphA2) increased after doxazosin treatment (50 μM) by 2.8±0.29-fold (n = 3; p = 0.048; Figure 5C).