We studied urokinase (uPA), tissue-type plasminogen activator (tPA), urokinase receptor (uPAR) and plasminogen activator inhibitor-1 (PAI-1) expression by in situ hybridization and by immunohistochemistry in 14 NF2 and 15 sporadic patients with 34 schwannomas. uPAR and vitronectin immunohistochemistry were also studied.