CD99 and Miyoshi myopathy: Malignant plasma cells from patients with MGUS, SMM, or MM (expanded clones) compared with normal plasma cells of all subjects (non-expanded clones) showed 439 significantly differentially expressed genes (p < 0.05, |logFC| > 1, logCPM > 1), including upregulation of the known MM markers [6,8,24] FRZB, DKK1, MYC, CCND1 and CCND3 and the proto-oncogene KIT [25], and downregulation of the B-cell antigens CD27, CD19 and CD79A and the tumor suppressor genes CD81 [26] and CD99 [27] (Fig 2F and S2 File).