Stx2B induces thrombotic microangiopathy in Adamts13^−/− mice. Stx2B 1.25 ng/g body weight was injected intravenously into 13 Adamts13^−/− mice and 13 Adamts13^+/− mice. (A) Platelet counts and hemoglobin levels. (B) Blood films for the indicated mice at 4 days (top, reticulocytes 19%) or 7 days (bottom, reticulocytes > 50%) after injection with Stx2B, demonstrating red cell fragmentation and reticulocytosis.