Importantly, partially ZAP-70 deficient mice showed similar clinical scores to the controls in the early stages of the experiment (Figure 1A), however, after day 52 we observed significantly milder arthritis in the ZAP-70+/− group (at day 61 scores were 10 ± 0.7 in the ZAP-70+/−- vs. 13.6 ± 0.6 in the ZAP-70+/+ groups) (Figure 1A). Here, ZAP70 is linked to arthritic joint disease.