IL6 and mental disorder: 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).