Quantitative PCR analysis showed remarkably high expression levels of A3B in the majority of MM/MGUS patients (range, 0 to 1.214; median, 0.991; control vs MM/MGUS, P = 0.00397; control vs MM, P = 0.001; Fig. 1a, left panel). This evidence concerns the gene APOBEC3B and Miyoshi myopathy.