HDAC4 and neoplasm: While miR-873 has been found to have either tumor-suppressive33 or tumor-promoting effects34 in different types of cancer, its expression was upregulated upon parathyroid hormone treatment in rat osteoblasts and downregulated HDAC4 protein expression, thereby stimulating MMP-13 expression in these cells.35 Building on our miRNA expression findings and previous research, we focused on hsa-miR-873-3p to determine whether TSA-EVs promote osteogenesis through the transfer of hsa-miR-873-3p.