Intravenous inoculation of BALB/c mice with M.tb strain CDC1551 successfully infected the CNS but did not produce granulomas in the brain and had low expression of brain chemokines and cytokines IL-1β, IL-6, TNF-α and IFN-γ, in contrast to the increased expression of these cytokines in the cerebrospinal fluid (CSF) of human TBM patients [16, 17]. This evidence concerns the gene IL6 and meningeal tuberculosis.