To assess if SIRT1 fragments are affected by OA, we performed DMM surgery on wild-type (wt) mice (CD1/129/J) to induce post-traumatic osteoarthritis (PTOA, figure 2A, B) and we also compared young (3 months) and old (15 months) mice (figure 2D, E). The gene discussed is SIRT1; the disease is osteoarthritis.