Serum CCL17 levels in MM patients before and after treatment. Mean serum CCL17 in 46 MM patients before and after LEN-DEX treatment (A) and in 28 MM patients before and after bortezomib-DEX treatment (B) at the onset of skin rash or after 2 cycles of treatments in cases of without rash formation. Serum CCL17 levels in 46 patients before LEN-DEX treatment, 32 patients who did not have rashes after LEN-DEX treatment, and 14 patients who developed rashes after LEN-DEX treatment (C); and serum CCL17 levels in 46 patients before LEN-DEX treatment, 25 patients who did not acquire a very good partial response (VGPR) after LEN-DEX treatment, and 21 patients who acquired VGPR or better after LEN-DEX treatment (D). (A-D) Each dot indicates 1 patient. (E) Kaplan-Meier curves of time to the next treatment in 14 patients who developed rashes vs 32 patients who did not have rashes after LEN-DEX treatment. (A-B) Bars indicate mean ± SEM and statistical significance was calculated by Wilcoxon matched-pairs signed rank test. (C-D) Bars indicate mean values and statistical significances were calculated by Mann-Whitney U tests. (E) Data of time to the next treatment were compared between the groups by using log-rank tests.