However, membrane BCMA (mBCMA) is expressed at relatively low levels on MM and DLBCL cells, in part due to shedding of its extracellular domain by membrane-associated ɣ-secretase, so unconjugated anti-BCMA mAbs also have poor efficacy in vivo [9,10]. Here, TNFRSF17 is linked to Miyoshi myopathy.