CXCL9 and tuberculosis: Although the development of specific immunological tests for diagnosis of bovine TB in wild felids has so far been relatively limited, measurement of mycobacterial antigen-specific IFN-γ production and expression of antigen-specific CXCL9 mRNA have shown diagnostic potential for detecting M. bovis infection in African lions (Olivier et al., 2015; Gumbo et al., 2022).