IL4 and generalized anxiety disorder: Lower levels of IL-10 and higher ratios of TNF-α/IL-10, TNF-α/IL-4, IFN-γ/IL-10, and IFN-γ/IL-4 were observed in the serum of GAD patients, showing significantly increased pro- to anti-inflammatory cytokine ratios, which suggests a distinct cytokine imbalance [104] (Figure 2d).