In preclinical tumor models, CAR‐Exos targeting antigens such as HER2, EGFR, and mesothelin have exhibited potent antitumor efficacy, inducing apoptosis in tumor cells and significantly inhibiting tumor growth without observable CRS, a frequent complication of cellular therapies.[258, 266] Mechanistically, CAR‐Exos can also influence the tumor microenvironment by downregulating immunosuppressive cells and triggering proinflammatory cytokine cascades. This evidence concerns the gene MSLN and neoplasm.