Although target antigens are expressed on both tumor and normal cells, not all kinds of CAR-T cell therapies exhibit observable on-target, off-tumor toxicities, such as targeting carcinoembryonic antigen (CEA), mesothelin (MSLN), and Interleukin 13 receptor, Alpha2 (IL13Rα2) [22–24]. The gene discussed is MSLN; the disease is neoplasm.