SDC1 and plasma cell myeloma: Six weeks after injection of the 5TGM1 mouse myeloma cell line (2 × 106/mouse), the elevated CD138+ mouse myeloma cell population (10.9% ± 1.2%, n = 6) and IgG2b levels (451 ± 10 μg/mL, n = 6) in the bone marrow of MM-5TGM1 mice indicated the successful proliferation of myeloma cells (Supplementary Figure 3A&3B).