MMP13 and osteoarthritis: In bone disease research, because MMP13 is highly expressed in the joint microenvironment of patients with osteoarthritis, Nagase et al. developed a peptide fluorescent probe with strong selectivity for MMP13 that will sever the connection between the response element and the carrier in an environment of high concentrations of MMP13, emitting intense fluorescence, which can clearly distinguish healthy joints from OA joints 8 weeks after destabilization of the medial meniscus (DMM) and is an effective tool for monitoring in the early stages of OA [172].