APCS and Stroke: These drugs have also been shown to be protective in animal stroke models: wild-type activated protein C (WT-APC) is cytoprotective but also an anticoagulant; the engineered mutant APCs known as 5A and 3K3A-APC retain the APC cytoprotection but without the same anticoagulant potency (Shibata et al., 2001; Fernandez et al., 2003).