HL-derived cell lines and LCLs express IL-27R. Four LCLs (LCL-1, -2, -3, -4) and three HL-derived cell lines (KMH2, L428, HDLM2) were tested for IL-27R cell surface expression and IL-27 binding by FACS analysis (x axis, log fluorescence intensity; y axis, cell number) as indicated in Materials and Methods. The filled gray line corresponds to controls.