Because the data described that the Il21 promoter in CKO CD4+ T cells had increased occupancy by the histone acetyltransferase CBP/p300 (Figure 2F) that subsequently facilitated Il21 transcription, we explored whether an interruption of CBP/p300 recruitment to the Il21 promoter attenuated Blimp-1 deficiency–mediated colitis at the initiation of disease. Here, IL21 is linked to colitis.