Expression of STAT proteins in T cells cultured with cytokines.

CD3-activated T cells were cultured with or without cytokines, as indicated. Cells were harvested at the indicated times, whole-cell extracts were prepared, and Western blots were performed with anti-STAT4 (top panel). The membranes were reprobed with anti-STAT1 (middle panel) and anti-STAT5 (bottom panel). Representative data from 3 separate experiments are shown.