CyTOF analyses of distinct markers involved in B cell regulation (e.g. MMSET or sXBP1), stemness (e.g. SOX2) and abnormal plasma cell differentiation (e.g. CD56) revealed different clusters among the B cell/plasma cell compartment and heterogeneous expression profiles within these defined clusters, in-between patients and among MGUS, SMM, MM or relapsed MM stages (72). The gene discussed is SOX2; the disease is Miyoshi myopathy.