CD38 and Miyoshi myopathy: We chose commonly used human MM cell lines for MM investigation, namely, H929 and MM.1S, which express CD38 and are lysed by daratumumab‐mediated immunological mechanisms.[23] Note that MM.1S cells are known to express lower baseline CD38 levels than H929 MM cells.[24] We also employed the human MM cell line, U266, which has two subtypes: U266‐CD38+ cells expressing CD38 and U266‐CD38− cells lacking CD38 expression.