A. 32D cells lacking or expressing IRS1 and/or IRS2 were serum starved and treated in the presence or absence of IL-3, supplied as WEHI-3B supernatant which contains 0.75% serum, or IL-4 (10 ng/ml) for 30 minutes. Cell lysates were prepared and the western blot was probed with anti-pAKT, anti-AKT, anti-BCL-2, anti-BCL-xL, anti-BAD, anti-BAD, anti BAX, anti-BAK and anti-tubulin antibodies. Blots were stripped and re probed no more than once. B. Densitometry was used to quantify bands. C. Lysates from 32D cells lacking or expressing IRS1 treated in the presence or absence of IL-3 were probed with anti BAK antibody.