ALK⁺ALCL cell line characterization and leukemia model amplify IL-22, which correlates with tumor burden. (A) Histogram of flow cytometric analysis of cell lines stained for IL-22R1 and pSTAT3 (Tyr705) antibodies. (B) Relative quantification of AHR, RORC, IL-22, IL-17F, and IL-26 by real-time polymerase chain reaction. (C) Zebra-plot of flow cytometry data showing intracellular levels of IL-22 with (Bref A +) or without (Bref A −) Brefeldin A, and PMA and ionomycin stimulation with Brefeldin A (P/I+ Bref A +) for 5 hours. (D) Kaplan-Meier survival plot of the Karpas299 leukemia-bearing SCID/NOD mice injected with PBS or HeFi-1. Serum levels of sIL-2Rα (E) and IL-22 (F) in Karpas299 leukemia-bearing SCID/NOD mice at day 21 after therapy.