BMAL1 and cartilage disease: Therefore, this review systematically describes recent research on the signaling pathways involved in Bmal1 regulating bone/cartilage metabolism, the upstream agents that modulate Bmal1 expression, and the various Bmal1 knockout mouse models to provide a deeper understanding of physiological bone/cartilage metabolism, as well as Bmal1’s potential value for treating bone/cartilage diseases.