In the ankle joint, overexpression of several proinflammatory cytokine genes started before arthritis onset, including TNFA from day 6 (Fig. 4A, p < 0.01) and IL-17A or IL-23A from day 8 (Fig. 4B,C, p < 0.05 and p < 0.01). This evidence concerns the gene TNF and arthritic joint disease.