TNFRSF13B and Miyoshi myopathy: BM tumors in the three different lines were composed of >10% GFP+CD138+B220−sIgM− PCs, which morphologically resembled human MM cells and exhibited a multifocal infiltration pattern in the BM; they also expressed typical MM markers including acid phosphatase, Bcma, Slamf7 and Taci, secreted immunoglobulins into the serum, and showed clonal IghV gene rearrangements (Fig. 1c–f and Extended Data Fig. 1a–c).