After downregulation of Bmal1 in knee chondrocytes, the expression of MMP3, MMP13, and ADAMTS4 increased, proving that chronic circadian rhythm disruption can promote the synthesis of matrix-degrading enzymes by inhibiting the expression of Bmal1, thereby mediating the occurrence of knee osteoarthritis [42]. The gene discussed is BMAL1; the disease is osteoarthritis, knee.