MAGE-A1-derived peptide is a short peptide sequence originating from the MAGE-A1 protein. Serving as a tumor-specific antigen, it can be recognized and activated by cytotoxic T lymphocytes (CTLs) to elicit an immune response against tumor cells expressing MAGE-A1. This immune response can result in the lysis and death of tumor cells. The peptide is utilized in research on tumor immunity.