IFN-γ is an important mediator of multiple immune pathways during inflammation (Schroder et al., 2004) and was found in the cerebrospinal fluid (CSF) of patients with pneumococcal meningitis, in concentrations significantly higher than in patients with meningococcal or haemophilus meningitis (Glimåker et al., 1994; Kornelisse et al., 1997; Coutinho et al., 2013; Grandgirard et al., 2013). This evidence concerns the gene IFNG and pneumococcal meningitis.