MMP13 and osteosclerosis: Eight weeks later, the researchers examined heterozygous mice for the lack of an allelomorph of Esrrg, and the expression level of ERRγ in joint tissue was reduced (Son and Chun 2018), the expression levels of MMP-3 and MMP-13 induced by DMM were dramatically reduced, and the OA symptoms of cartilage erosion, subchondral osteosclerosis and osteophyte formation were significantly decreased compared with those of normal DMM mice (Zhao et al. 2019).