This study further confirms the merits of BCG and the importance of route of administration to render a non-specific protective response.  Furthermore, the likely mechanism is nitric oxide as previously predicted.  In studies when evaluated for nitric oxide, it was found that BCG triggers cytokine-dependent, IFN-γ and TNF-α and/or IL1-β, inducible nitric oxide synthase pathways (NOS) expression and nitric oxide release by both alveolar macrophages and non-immune cells, including airway epithelial cells.   www.medpagetoday.com/.../86410