A meta-analysis reported that the pooled sensitivity and specificity of CSF-ADA for the diagnosis of TBM were 89% and 91%, respectively (the cutoff values ranged from 6 to 15 IU/L) (Pettersson et al., 1991; Pormohammad et al., 2017; Ekermans et al., 2017), which suggests it is a reliable and fast diagnostic tool for TBM given the poor sensitivity of acid-fast staining and molecular assays for the CSF (Ho et al., 2013; Mai and Thwaites, 2017). The gene discussed is ADA; the disease is meningeal tuberculosis.