Recent efforts have identified potential therapeutic mAbs by defining alternative or novel MM target antigens, i.e., CD40 [12, 13], interleukin-6 receptor [14], HM1.24 [15, 16], CD74 [17], CD47 [18], TRAIL-R1 [19], CS1 [20], PD-1 [21], as well as by conjugating mAbs with classic or novel drugs to specifically kill MM cells, i.e., CD56-maytansinoid (DM1) [22], CD138-DM1/DM4 [23]. Here, CD74 is linked to Miyoshi myopathy.