Neoplastic plasma cells express significantly higher levels of CD126 than normal plasma cells derived from the same bone marrow in patients with MGUS.

Box and whisker plots showing the minimum; 25th, 50th, and 75th percentiles; and maximum expression of CD126 (IL-6 receptor alpha-chain) by phenotypically neoplastic and normal plasma cells identified using the sequential gating strategy shown in Figures 1 and2. Values shown are the K-S D values for the separation of test (CD126-PE fluorescence) and control (CD3-PE fluorescence) cumulative frequencies. The P value shown is for the difference in expression levels between paired phenotypically normal and neoplastic plasma cells, respectively (Wilcoxon signed-rank test).