PAI‐1 deficiency caused by mutations has been reported to lead to a moderate bleeding disorder.1 On the flip side, high levels of PAI‐1 were reported in some families with thrombophilia.2, 3 Blood PAI‐1 antigen levels and activity are strongly correlated and both measures have been used to study the role of PAI‐1 in cardiovascular disease. This evidence concerns the gene SERPINE1 and thrombophilia.