Mesothelin (MSLN) is a cell surface glycoprotein that is highly overexpressed in various malignant tumors but is restricted to mesothelial cells in normal tissues, reducing the risk of off-target toxicity.13,14 Moreover, the expression of MSLN is associated with chemotherapy resistance, poor prognosis, and increased tumor aggressiveness and may facilitate tumor invasion and metastasis.15 These features make MSLN an attractive target for CAR-T and CAR-NK cell immunotherapy in solid tumors. The gene discussed is MSLN; the disease is cancer.