The La Jolla team further probed the functional consequences of this derivatization. They produced plasminogen free of oxidized phospholipid by treatment with phospholipase in vitro, and then examined the effect of both the oxidized phospholipid-derivatized plasminogen and of unmodified plasminogen on thrombolysis in vitro. Curiously, they found that removal of the oxidized phospholipid moiety actually prolonged the clot lysis time. That is, the oxidative modification actually seems to promote the thrombolytic potential of plasminogen. This in vitro assay, while commonly used, may not extrapolate directly to humans. Yet, if the modification of products of lipoprotein oxidation of plasminogen enhanced its thrombolytic ability in vivo, it would provide yet another example of an unexpected beneficial effect of a mechanism usually considered a culprit in atherothrombosis. Indeed, the more we learn, the more counterregulatory processes seem the rule rather than the exception in the control of atherothrombosis, as in other biological processes.