Increased interleukin-26 in the peripheral joints of patients with axial spondyloarthritis and psoriatic arthritis, co-localizing with CD68-positive synoviocytes by Hammitzsch, A, Ossadnik, A, Bachmann, Q, Merwald-Fraenk, H, Lorenz, G, Witt, M, Wiesent, F, Mühlhofer, H, Simone, D, Bowness, P, Heemann, U, Arbogast, M, Moog, P, Schmaderer, C