Knockdown of Mer inhibits survival signaling and promotes caspase cleavage. Control (shCont) and Mer knockdown (shMer1A) 697 cells were exposed to 10 μM 6-MP, 150 nM VP-16, or medium only (Untrt) for 24 hours (A) or 40-60 minutes (B). Whole-cell lysates were prepared and expression of the indicated proteins (p- denotes a phosphorylated protein) was determined by Western blot analysis. Blots representative of 3 independent experiments are shown.