CD38 and Miyoshi myopathy: Relapsed patients are mostly treated with triple therapies, but triple-refractory MM patients (refractory to a PI, an immunomodulatory drug (IMID) and an anti-CD38 mAb) and penta-refractory MM patients (refractory to two PIs, two IMIDs and an anti-CD38 mAb) are not uncommon.