On the cover: Histologic sections of ankle joints were immunostained with oncostatin M (2 μg/ml) in collagen-induced arthritic mice treated with lentiviral-osteopontin short hairpin RNA. Original magnification ×400. Su, C.-M., Y.-C. Chiang, C.-Y. Huang, C.-J. Hsu, Y.-C. Fong, and C.-H. Tang. 2015. Osteopontin promotes oncostatin M production in human osteoblasts: implication of rheumatoid arthritis therapy. J. Immunol. 195: 3355–3364.