tPA (Tissue-type plasminogen activator) converts plasminogen to plasmin, a primary fibrinolytic protease.1 tPA and its inhibitor, PAI-1 (plasminogen activator inhibitor-1), have been detected in thrombi from patients with MI.8 PAI-1 and protease nexin-1 have also been detected in AIS thrombi.14 Variation in fibrinolytic proteins and their inhibitors incorporated in thrombi may impact on resistance to therapeutic thrombolysis. This evidence concerns the gene PLAT and androgen insensitivity syndrome.