SDC1 and Miyoshi myopathy: To verify if the differential expression of MCT1 at the mRNA level was borne out in the membrane-based protein expression of MCT1, patients with MGUS (N = 10), MM patients with elevated serum LDH levels (N = 15), and MM patients with non-elevated serum LDH levels (N = 15) had immunohistochemical (IHC) assessments of MCT1 on the primary CD138 + MM cells in their BM core biopsy specimens.