Plot of absolute RHAMM expression versus RHAMM ratios for 14 MM patients. Elevated expression of RHAMM is significantly related to an increase in RHAMM^-exon4 expression within MM patients. RHAMM expression within purified MM CD138⁺ PCs was determined by quantitative RT-PCR analysis. Relative RHAMM expression was normalized to the lowest patient expresser. RHAMM ratio (± standard error) was determined as described. Statistical comparison used the Pearson correlation coefficient.