The therapeutic efficacy of rutin was evaluated in murine hypertensive ICH models.<h4>Results</h4>We identified a distinct SELL-high CD8<sup>+</sup> T cell subpopulation (scPAS<sup>+</sup> cells) exhibiting comprehensive effector dysfunction, characterized by downregulation of cytotoxicity genes (GZMA, GZMB, GNLY, NKG7, and CCL5). Here, CD8A is linked to Hypertension.