Effect of interleukin (IL)-17 on the osteoclastogenesis. Osteoclastic activity was assessed by the development of resorption pits in calcium phosphate-coated slides as described in Materials and methods. Synovial tissue (ST)-derived inflammatory cells (n = 6) were cultured with incremental doses of IL-17 in the absence or presence of indomethacin on calcium phosphate-coated slides for 2 weeks and examined for the development of resorption pits. The ratio to the number of resorption pits in medium alone was plotted. Bar indicates the median value. *P < 0.05 vs. medium alone (by Wilcoxon signed-rank test).