To assess whether the impairment of osteogenic differentiation in BMMSCs from MM patients was due to abnormal Notch signaling pathway, we examined the level of genes involved in Notch signaling pathway by RT-PCR, including Notch receptors Notch1 and Notch2, Notch ligands Jagged-1 and Deltalike-1, and Notch signaling downstream Hey-1, Hey-2, Hes-1, Hes-5 and Hey-L. Here, HES5 is linked to Miyoshi myopathy.