Several clinical trials are currently active testing HER2 CAR-Ts for the treatment of several HER2-positive tumors aside from breast, such as brain malignancies (NCT02442297, NCT01109095, NCT03500991), sarcomas (NCT04995003, NCT00902044), lung cancer (NCT03198052), pleural and peritoneal metastasis (NCT04684459), ependymoma (NCT04903080), and pancreas tumors (NCT01935843). Here, ERBB2 is linked to ependymoma.