<n0:ComplexDefinition xmlns:n0="http://ncicb.nci.nih.gov/xml/owl/EVS/ComplexProperties.xsd#"><n0:def-definition>An attenuated strain of Mycobacterium bovis with non-specific immunoadjuvant and immunotherapeutic properties. Although the mechanism of its anti-tumor activity is unclear, immunization with BCG (Bacillus Calmette-Guerin) likely activates a Th1 cytokine response that includes induction of interferon. Vaccination with BCG may be immunoprotective against infection with Mycobacterium tuberculosis. (NCI04)</n0:def-definition><n0:def-source>NCI</n0:def-source></n0:ComplexDefinition>