GZMB and Miyoshi myopathy: Data showed that except the production of granzyme B by CAR‐T cells cocultured with U266 similar to control T cells, CD38‐CAR‐T cells stimulated by MM cell lines generated significantly increased level of IL‐2, IL‐3, IL‐8, IL‐9, GM‐CSF, granzyme B, IFN‐γ, and TNF‐α than control T cells (Figure 3F).