Kinetics of serum levels of IL-4 and IFN-γ after single injection of αGalCer. C57BL/6, NZB/W, and Jα281–/– C57BL/6 mice at age 8–12 weeks or 4 weeks were given a single injection of αGalCer or PBS/vehicle control, and serum levels of IL-4 and IFN-γ were measured at 2, 6, and 18 hours after injection. (a and b) Data from 8- to 12-week-old mice. (c and d) Data from 4-week-old mice. Bars show means of ten mice, and brackets show standard errors.