Taking a bird’s-eye view, we conjecture that the four clusters of biomarkers that predict anxiety disorders are direct and indirect indicators of the functioning of the immune system, which functions in an M2 or alternative activation state (and produces cytokines like interleukin (IL-10) or interleukin 13 (Il-13)) or an M1 or classical activation state (producing cytokines like interleukin 6 (IL-6) or tumor necrosis factor-α (TNFα)) [23]. Here, IL13 is linked to anxiety disorder.