While it is known that serum IL-6 concentrations increase with age and systemic IL-6 appears central to the pathophysiology of physical function decline, as well as many chronic diseases [244,245], “inflammaging”, which is systemic mild inflammation in the absence of an apparent infection associated with the process of biological aging, also contributes to an array of age-related diseases including OA [246,247,248]. This evidence concerns the gene IL6 and infection.