NF-κB expression in GM-CSF–stimulated TF-1 cells. Whole cell lysates were prepared from growth factor–deprived TF-1 cells stimulated with GM-CSF for 0 to 24 hours. The protein content of 4 × 10⁵ TF-1 cells was loaded in each lane of a 10% polyacrylamide gel. The membranes were blotted with anti-p50, anti-p52, anti-p65, or anti-IκBα antibodies and detected with ECL. A representative blot from one of five independent experiments is shown.