FN1 and urothelial carcinoma: Work by Pryor, Ciao, and Sasaki all have reported a direct anti-proliferative effect of BCG.[5,6,15] Liu et al demonstrated that BCG, as a consequence of its interaction with cell surface bound fibronectin, abrogates invasion and motility of urothelial carcinoma cell lines.[7] Cellular internalization of BCG, with resultant alterations in reactive oxygen species and nitric oxide, has been proposed as a mechanism contributing to direct BCG mediated cytotoxicity.