Blimp-1 binds to the mouse Il2 and Fos genes. (A) ChIP of endogenous Blimp-1 bound in various regions of the Il2 and Fos genes. WT purified CD4⁺ T cells were stimulated in vitro for 6 d, restimulated with PMA and ionomycin for 4 h, and cross-linked for ChIP. Data represent fold enrichment of αBlimp-1 antibody over control antibody. Snail3 is used as a negative control. NR is a region containing no Blimp-1 consensus sequence. Results shown are the mean and SEM from four to five different experiments. (B) Representation of the Il2 and Fos mouse genes, with the sites shown in A marked. Sites enriched for Blimp-1 binding are marked with asterisks. The −4,990 site at the Fos gene is conserved between the human and mouse genes. No sites found at the Il2 gene are conserved between mouse and human.