BD is accompanied by: i)moderately increased plasma levels of pro-inflammatory cytokines, such as interleukin(IL)-6 and tumor necrosis factor-α; ii) increased protein and mRNA levels of IL-1β, andIL-1RA in the frontal cortex of post-mortem bipolar patients (12,13); and iii) increasedacute phase protein levels, including haptoglobin and C-reactive protein (CRP), as wellas complement factors, such as plasma C3 or C4 concentrations (12). Here, C3 is linked to Behcet disease.