Co-culture of MM cells and MM-MSCs induced activation of Notch signaling via jagged-2/notch-2, leading to increased expression of Hes1, Hey2, or Hes5 in both cell types; in turn, activation of Notch signaling in MM-MSCs led to a decrease in miR-223 expression, although the underlying mechanism was not addressed. The gene discussed is HES1; the disease is Miyoshi myopathy.