The CD26+/CD24+-enriched cells from sarcomatoid H28 cell lines and the CD26+/CD24−-enriched cells from epithelioid H226 cell lines showed higher resistance to chemotherapy and higher invasion potential, whereas MM cells with CD26 and CD24 knockdown were more responsive to chemotherapy, suggesting that CD26 and CD24 are potential CSC markers for certain histological subtypes of MM. The gene discussed is DPP4; the disease is Miyoshi myopathy.