Lymphocytes have been shown to play a negative role in ovx- and arthritis-induced osteoporosis by producing pro-inflammatory cytokines and RANKL, thereby inducing osteoclasts and inhibiting osteoblasts (Cenci et al. 2000, Pacifici 2008, Islander et al. 2011b). This evidence concerns the gene TNFSF11 and arthritic joint disease.