The amount of antigen stimulation tunes CD8+ T cells for IL-12-conditioned effector maturation. Naive OT-I T cells cultured in various conditions were transferred into new wells containing media alone or IL-12 (0, 0.2, 2, and 20 ng/ml). (A) The OT-I cells were evaluated for IFN-γ production by ICS and flow cytometry analysis at 72 h. (B) The OT-I cells were evaluated for cytolylic ability in a standard 4-h chromium release assay at 72 h. (C) ICS for phospho-STAT4 at 48 h. (D) IL-12 (2 ng/ml) was added at 0, 24, and 48 h after OT-I T cells transfer. OT-I T cells were harvested and evaluated for IFN-γ production by ICS and flow cytometry analysis at 72 h.*, P < 0.05; **, P < 0.01. Experiments shown were repeated three times with identical outcomes.