IL-6 gene variation is not associated with increased serum levels of IL-6, muscle, weakness, or frailty in older women - Walston, J.; Arking, D.E.; Fallin, D.; Li, T.; Beamer, B.; Xue, Q.; Ferrucci, L.; Fried, L.P.; Chakravarti, A. (Experimental Gerontology, 2005)