A Fas cell surface death receptor (FAS)-induced apoptosis was thought to take an important role in T-cell survival.48 By restraining the activity of caspase 3, IL12 could inhibit FAS-dependent apoptosis in murine experiments.47 In another murine colitis model, FAS-mediated T-cell apoptosis was also highlighted because that MRL/MpJ-lpr(fas) mice lacking Fas function developed colitis that responds poorly to anti-IL12 treatment.45 Whether CD4+ T-cell apoptosis induced by anti-IL12p40 treatment was also dependent on FAS-mediated signaling remained to be further verified. This evidence concerns the gene CD4 and colitis.