B7H3.BC CAR-T cells showed reduced H3K27ac signal intensity at loci associated with T cell exhaustion (e.g., BATF3, TOX2) and tonic signaling (e.g., DAPK1, IL23R) (Figure S9B, C), while H3K27ac signals at stemness-associated loci (e.g., KLF2, MYC) were elevated (Figure S9D). Here, KLF2 is linked to breast cancer.