Western blot using Stat5a polyclonal antibody (Cat # PAB11328) shows detection of Stat5a 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.