Despite several more courses of chemotherapy (including two cycles of VRD, two cycles of cyclophosphamide–etoposide–cisplatin–dexamethasone (DECP), and three cycles of daratumumab–melphalan–dexamethasone–thalidomide (DARA+MPT)), the patient presented unbearable bone pain throughout the body, which was further confirmed to be the result of osteolytic lesions by MM, with extremely elevated levels of serum IgA (1314 mg/dL) and FLC-κ (78.7 mg/dL), as well as sustained proplasmacytes (6%) at the time of admission. Here, CD79A is linked to Miyoshi myopathy.