IL-1β concentration did not vary from baseline or between the control and affected joint following induction of either model, although a non-significant peak was present at 6 h post-induction of both synovitis and lavage (synovitis IL-1β baseline: 715 ± 620 pg/mL; synovitis IL-1β peak: 2536 ± 2004 pg/mL at 6 h; lavage IL-1β baseline: 286 ± 269 pg/mL; lavage IL-1β peak: 1001 ± 888 pg/mL) (Fig. 4a-b). This evidence concerns the gene IL1B and synovitis.