CXCR4 and Miyoshi myopathy: To further analyze the functionality of the chemokine receptors expressed by MM cells, we performed a chemotaxis assay to analyze the ability of MM cells to migrate toward 500 ng/ml CCL3, CCL4, CCL5 (CCR1, CCR3 and CCR5 ligands, respectively); CCL25 (CCR9 ligand); CXCL9 or CXCL10 (CXCR3 ligand); or 250 ng/ml CXCL12 (CXCR4 ligand).