Although the exact mechanism and biological relevance underlying IL-10 increase in AdV 7 infected patients remain to be investigated, it is possible that the immune system has detected the irregular inflammation in the airway and has tried but failed to restore the cytokine balance by upregulation of anti-inflammatory cytokines like IL-10, as elevation of IL-10 is very common in viral and bacterial infections (29). Here, IL10 is linked to bacterial infectious disease.