Western blot analysis of extracts from UT-7 cells, untreated or treated with erythropoietin (EPO; 3 units/ml for 5 min), TF-1 cells, untreated or treated with Human Granulocyte Macrophage Colony Stimulating Factor 100ng/ml for 10 min), and NK-92 cells, untreated or treated with Human Interleukin-2 100ng/ml for 10 min), using Phospho-Stat5 (Tyr694) antibody or total Stat5 antibody.