SDC1 and Miyoshi myopathy: Focusing on CD138+ cells to further characterize MM CTCs and BMPCs, the immunophenotypes and morphology of MM CTCs (CD138+ circulating rare cells) and BMPCs include subsets with CD56 and CD45 signals with BMPCs showing PC clusters, binucleated PCs, apoptotic PCs, and CD138− candidate PCs, as previously observed [25] (Figure 3A).