SOX9 and cyclic hematopoiesis: Additionally, our results demonstrated that hBMSC-EVs reversed downregulation of anabolic gene expression (COL2A1, SOX9, PRG4, ACAN, BCL2, and COMP) and upregulation of catabolic gene expression (COLX, IL1B, MMP-13, and ALPL) in IL-1β-stimulated OA-CH.