HDAC4 and cancer: While miR-873 has been found to have either tumor-suppressive33 or tumor-promoting effects34 in different types of cancer, its expression was upregulated by PTH treatment in rat osteoblasts, leading to a reduction in HDAC4 protein levels and subsequently stimulating MMP-13 expression in these cells.35 Our study showed that histone acetylation-mediated HSMMs produce EVs containing excessive miR-873-3p, which can be directly transferred to hBMSCs and are pro-osteogenic, proliferative, and migratory, all of which are essential for bone formation.