Effect of A fumigatus culture filtrates on HUVEC differentiation, migration, and capillary tube formation on Matrigel. Compared with control wells inoculated only with growth medium (A-B), differentiation and capillary network formation by HUVECs were significantly inhibited in wells inoculated with A fumigatus (Af293) culture filtrate (C). Capillary network formation was not affected by ΔlaeA culture filtrates (D), whereas complementation of the laeA defect restored the inhibitory activity of A fumigatus culture filtrates against HUVEC function (E). ΔgliP exhibited incomplete inhibitory activity against HUVECs (F-G), suggesting that gliotoxin is one of several secondary metabolites that mediate the antiangiogenic effects of A fumigatus culture filtrates. *P < .01; **P < .001. Except where indicated otherwise, P values refer to the comparison with control wells.