TRAIL and Fas are induced by IFN-α in MM primary cells. Purified CD138⁺ plasma cells from 11 patients with MM were cultured with IL-6 (20 U/mL) alone or in combination with IFN-α (1000 U/mL) for 24 hours. Total RNA was isolated from 6 cases and mRNA expression levels of (A) TRAIL/Apo2L and (B) Fas/Apo1 were quantified using TaqMan Gene Expression “Assays on Demand” (ID Hs00531110 m1, Hs00234355 m1) and β-actin as a reference. (C) Resazurin assay. In parallel cultures preincubation with IFN was followed by a 24-hour incubation with the agonistic anti-Fas antibody CH-11 and subsequent addition of resazurin. After 3 hours of incubation the wells were analyzed using a 96-well microplate fluorometric reader. Results are presented as mean ± SD (n = 3).