We evaluated expression patterns of full-length HMMR (HMMR-FL) and four alternatively spliced transcripts: HHMR V1, V2, V3, and V4 (Supplementary Fig. 1A, B) in CD138 + plasma cells (PCs) obtained from bone marrow (BM) aspirates of MM patients and healthy donors (HD) (Fig. 1A, B) using RT-PCR and DNA fragment analysis followed by capillary electrophoresis. Here, SDC1 is linked to Miyoshi myopathy.