Many clinical trials are also evaluating the safety and efficacy of CAR-T therapy in solid tumors such as renal cancer, pancreatic cancer, hepatocellular carcinoma, breast cancer, colorectal cancer, ovarian cancer, brain cancer, and lung cancer by targeting various antigens, including CEA, GD2, mesothelin, TnMUC1, PSCA, HER2, glypican 3(GPC3), GUCY2C, and CD19 [151,152]. The gene discussed is ERBB2; the disease is breast cancer.