IL6 and viral infectious disease: An array of inflammatory cytokines are increased in obese tissues, such as tumor necrosis factor alpha (TNF-α), C-reactive protein (CRP), plasminogen activator inhibitor-1 (PAI-1), interleukin (IL)-6, IL-1β, CCL2, and Toll-like receptors (TLRs) of the innate immune system, which may have additional implications in responses to vaccination and viral infections [105,106].