Table 1B shows the individual CSF studies conducted to our knowledge thus far regarding CSF cytokines, with pro-inflammatory IL-6 standing out as increased in schizophrenia. Figure 1 shows a relative representation of the individual studies regarding CSF cytokine changes (26) in a bubble plot, indicating that anti-inflammatory IL-2 may also be elevated in CSF in schizophrenia. However, cytokine levels in CSF are lower than in blood and a recent study by Singh et al. demonstrated potential limitations in sensitivity of multiplex cytokine assays in CSF studies of mental disorders (27). This evidence concerns the gene IL6 and psychiatric disorder.