STAT5A protein expression in BM-derived macrophages from WT, HZ, and STAT5A null mice. Extracts (30 μg of protein per lane) of BM-derived macrophages from WT (+/+; lane 1), HZ (+/−; lane 2), and null (−/−; lane 3) mice were analyzed by SDS-PAGE followed by immunoblotting with (A) anti-STAT5A, (B) anti-STAT5B, or (C) anti-STAT1 as described in Materials and Methods. The membranes were developed by enhanced chemiluminescence.