M. tuberculosis challenge experiments demonstrated that CD84 suppresses both T and B cells during M. tuberculosis pathogenesis: CD84-deficient mice had elevated T cell numbers, activated T cells, and release of certain TB-related cytokines, especially IFN-γ (Fig. 3), as well as increased B cell activation, IgA production, and GC B cell clustering (Fig. 4). The gene discussed is CD84; the disease is tuberculosis.