Although the precise mechanism of eosinophil‐induced hypercoagulability is still unclear, contributing factors probably include initiation of the clotting cascade by expression of tissue factor, endothelial injury by major basic protein (MBP), stimulation of thrombus formation by binding to heparin and neutralizing its anticoagulating effects by eosinophilic cationic protein.7, 8. The gene discussed is MBP; the disease is thrombophilia.