We detected the mRNA expression of DLD in primary MM cells isolated from patients, and CD19+ B cells from three healthy individuals were used as controls, the quantitative results of reverse transcription-polymerase chain reaction (RT-qPCR) showed that the mRNA level of DLD in plasma cells of MM patients was higher than that of healthy controls (Fig. 2A). The gene discussed is CD19; the disease is Miyoshi myopathy.