Id3 restricts chromatin accessibility at specific gene loci. Naïve CD4⁺ T cells were cultured under Th1 polarization condition for 4 days. CD62^lo effector cell population were sorted for ATAC-seq and RNA-seq libraries preparation. (A) differential ChrAcc sites were assigned to genes less than 50 kb upstream and downstream. DEGs associated with opened chromatins in Id3-cKO Th1 cells were subject to gene ontology (GO) term analysis. (B) Motif analysis of opened chromatin sites in Id3-cKO Th1 cells. (C) Differential accessible windows along the gene Pdcd1 regulatory loci. Data were collected from 3 independent experiments. ATF, activating transciption factors; IRF, interferon regulatory factor; mRNA, messenger RNA.