By adding the plasminogen inhibitor EACA or α2-antiplasmin in addition to plasminogen we saw strong inhibition of the plasminogen-dependent inhibition of tumor cell migration across the BBB (0.85+/-0.26% and 0.89+/-0.32%, respectively) indicating that plasminogen is necessary for crossing of the BBB model (Fig. 4). Here, PLG is linked to neoplasm.