Differential expression of Hh genes between CD138⁺ PCs from healthy persons, MGUS, MM, and PCL patients, and MM cell lines. Gene array analysis demonstrates the differences in expression of Hh pathway-related genes between normal (n = 4) and malignant PCs in MGUS (n = 11), MM (n = 133), and PCL (n = 9) patients, and MM cell lines (n = 23). Bars represent mean ± SEM. The statistical significance of differences among the groups was assessed using Kruskal-Wallis test. P < .05 was considered significant.