Afamitresgene autoleucel (afami-cel) targeting the cancer-testis antigen MAGE-A4 in patients with an HLA*02:01 allele achieved a 37% overall response rate in heavily treated patients with synovial sarcoma (SS) and myxoid round cell liposarcoma (MRCLS) [27, 28], leading to the first FDA approval of a genetically engineered ACT in solid tumors. This evidence concerns the gene MAGEA4 and myxoid/round cell liposarcoma.