Western blot using affinity purified anti-STAT5 antibody shows detection of Stat5 protein in HeLa cell extract (arrowhead). Primary antibody was used at a 1:600 dilution reacted overnight at 4°C. Secondary antibody was used at 1:20,000. Molecular weight estimation was made by comparison to prestained MW markers. Identity of the upper and lower bands is unknown. Personal communication, Luanne Lukes, NCI, Bethesda, MD