CXCR4 and Miyoshi myopathy: In order to estimate the magnitude of CXCR4 expression in MM cells compared to normal non-malignant cell populations that have previously been described as CXCR4 positive (Aiuti et al, 1999; Honczarenko et al, 1999; Burger & Kipps, 2006; Brave et al, 2010), we compared CXCR4 expression levels in individual MM patient samples judged CXCR4 positive by flow cytometric and immunohistochemical assessment (CXCR4+ MM).