SDC1 and Miyoshi myopathy: To validate our findings in a more physiological setting, we isolated primary CD138+-plasma cells from MM patients (see Supplementary Table 1 for patients' characteristics), split the samples into four groups and analyzed radiotracer uptake: (i) untreated/MET, (ii) untreated/FDG, (iii) 24 h Bz/FDG, (iv) 24 h Bz/MET.