Ablating CTCF impairs T _EFF program but favors T _MP program. (A) Volcano plot showing DEGs between WT and Ctcf^−/− early T_EFF cells isolated on 4 dpi, with values denoting gene numbers. (B and F) GO terms for genes downregulated (B) or upregulated (F) in Ctcf^−/− compared to WT early T_EFF cells, as determined with the DAVID Bioinformatics Resources, with dot color denoting enrichment scores. (C and G) Heatmaps of select downregulated (C) or upregulated genes (G) in Ctcf^−/− compared to WT early T_EFF cells. (D and H) Detection of Tbet (D) and Tcf1 (H) proteins by intranuclear staining in WT and Ctcf^−/− early T_EFF cells isolated on 4 dpi. Values in half-stacked histographs (D) denote gMFI, and those in separate histographs (H) denote percentage of Tcf1⁺ subset. (E) Detection of KLRG1 and IL-7Rα proteins by surface staining in WT and Ctcf^−/− early T_EFF cells isolated on 4 dpi, with values denoting percentages of KLRG1^hiIL-7Rα⁻ and KLRG1^loIL-7Rα⁺ subsets. Data in D, E, and H are from two independent experiments, and cumulative data are means ± SD. ***, P < 0.001 by two-tailed Student’s t test. gMFI, geometric mean fluorescence intensity.