microRNA expression pattern in MM and normal donors. (A) miRNA analysis was performed on total RNA isolated from bone marrow (BM) CD138⁺ MM cells, normal BM (HD)–derived CD138⁺ counterparts, and MM cell lines (MM.1S, RPMI8226, U266). The heat map was generated after unsupervised hierarchical cluster analysis of all unfiltered data. Differential expression of miRNA is shown by the intensity of red (up-regulation) versus blue (down-regulation). (B) Supervised hierarchical clustering analysis was performed using the ANOVA test. Differential expression of miRNA patterns is shown by the intensity of red (up-regulation) versus blue (down-regulation). (C) Differential distribution of each indicated miRNA in all MM patients (MM) compared with healthy donors (HD): mean values were compared using Mann-Whitney U rank sum test; bars indicate standard errors; P value (*) for each miRNA is indicated.