Mostly upregulated B cell signaling regulators (such as MMSET, MYD88, c-Myc, CXCR4, and Notch-1), stem cell marker KLF-4, ABC transporter CD243, and PC aberrant markers (CD47 and CD52) were noted from immature to naive B cells in all MM stages with upregulation of sXBP-1 (T1) and CD200 (T3 and N) only in MGUS or SMM (Figure 3C), showing signaling perturbations in both premalignant and active MM stages. Here, CD200 is linked to Miyoshi myopathy.