Normal plasma cells (NCs) and MM cells (MMCs) were differentiated by (1): MMC-specific mutations (MYC, CCND1/CCND3, FGFR3/MMSET, MAF/MAFB) (9, 10) (2); karyotypic changes (17p-, 13q14-, t (11, 12) /IgH-FGFR3, t (8, 12) /IgH-CCND1, etc.)(12, 13) (3); immunophenotype (CD38dimCD138+CD19-CD20+CD56+CD28+CD27- and CD38+CD138+CD19+CD20-CD56-CD28-CD27+ NCs) (14). Here, SDC1 is linked to Miyoshi myopathy.