We did find that RIPK3–/–Casp8flox/flox mice have slower induction of arthritis than RIPK3–/– mice, potentially owing to interactions from the remaining 129 background present in both Casp8flox/flox and RIPK3–/– strains despite being backcrossed to B6 for over 12 and 4 generations, respectively [26, 37, 38, 46]. Here, RIPK3 is linked to arthritic joint disease.