Closed chromatin impacts CXCR5 gene expression. (A) Ranked expression of selected epigenetic modifiers. Epigenetic modifiers were grouped according to functional attributes (ie, chromatin remodeling, histone chaperone, histone modification) and by transcription activity. (B) PCA plots obtained from the ATAC-Seq cut count data. The top 10% of ATAC-Seq peaks (merged between subsets) were used to create the PCA plot. (C) Overview of the ATAC-Seq signal around the CXCR5 gene loci. The ATAC-Seq signal is shown for different loci (marked in gray) at which differential binding was detected in ≥1 sample. The black box shows the TSS region where there is clear equivalence between fCD8 and GCTfh ATAC-Seq signals, whereas very low signals were observed for non-fCD8s and naive CD8⁺ T cells. (D) Regions of predicted transcription factor footprints in respective cell subsets. The pie charts show the relative Wellington bootstrap scores for each subset against all others acting as a proxy for the relative TF activity observed in that region. The bars indicate the extent of the predicted TF footprint, with colors assigned to each subset. Footprints with unassigned TFs are also included.