T-cell stimulation induces hyperacetylation of the il2 promoter. ChIP assays were performed using antiacetylated H4 antibodies in naive (N) and in Th1 cells resting (R) or stimulated (St) for 6 hours with anti-CD3 and anti-CD28. PCR amplifications with primers for the (A) il2 or the (B) CD3ϵ promoters were done with different amounts of sample to confirm linearity of the amplification. One experiment of 2 with similar results is shown. Numbers below input bands indicate relative (to naive cells) amount quantified using qPCR. Graph shows relative (to naive cells) intensity of amplified complexes from all experiments (mean + SEM).