SMAD9 and Miyoshi myopathy: Another miRNA that directly targets a SMAD protein is the aforementioned miR-203a-3p, which regulates osteogenic differentiation of MM-MSCs not only via regulation of the canonical WNT pathway but also by targeting SMAD9. Although miR-203a-3p levels are lower in MM-MSCs compared to normal donor MSCs, a decrease in the expression levels of miR-203a-3p was observed upon osteogenic induction in normal MSCs, while no significant change was observed in MM-MSCs.