Effects of CD39 targeting on thrombus formation and hemostasis. (A) Comparison of occlusion time measurements of ferric chloride–induced thrombosis in carotid arteries of mice administered non–targ-CD39, targ-CD39, saline, or single-chain antibody (scFv) controls (n = 8 each) at an equimolar amount in regard to the scFv component in the targ-CD39 group. (B) Comparison of bleeding time in mice determined by tail transection between non–targ-CD39, targ-CD39, and saline (n = 5 each). Doses administered were activity matched: eg, low-dose non–targ-CD39 of 0.8 mg/kg corresponds to low-dose targ-CD39 of 0.4 mg/kg. Measurements were analyzed with a Gehan-Breslow-Wilcoxon survival analysis and subsequently represented as bar graphs (*P < .05; **P < .01).