Apoptotic pathway components have been postulated to function during several stages of thrombopoiesisis and hemostasis, including platelet formation from megakaryocytes, platelet clearance, and platelet activation. However, the new data from White et al provide evidence that the intrinsic apoptotic initiator caspase-9 is dispensable for all of these steps under normal physiologic conditions. Figure adapted from White and Kile10 with permission.
