RIPK1 and infection: Card19lxcn BMDMs also exhibited a significant defect in cell death following infection by Yersinia pseudotuberculosis (Yptp), which activates cell-extrinsic caspase-8- and RIPK1-dependent apoptosis in response to Yptb blockade of IKK- and MAPK-signaling [6,49,50], as well as in response to staurosporine (Sts), a broad-spectrum kinase inhibitor that induces cell-intrinsic apoptosis and also activates caspase-8 in myeloid cells [51–53] (Fig 1E and 1F).