MAGEA4 is a cancer/testis antigen that functions as an oncogene promoting tumor development through multiple mechanisms. Primarily, MAGEA4 regulates cell proliferation by inhibiting G1 phase cell cycle arrest and negatively regulating p53-mediated apoptosis 1. At the molecular level, MAGEA4 forms complexes with TRIM28 to accelerate P53 degradation via ubiquitination 2. MAGEA4 also stabilizes RAD18 protein, facilitating recruitment of Y-family DNA polymerases to enable DNA replication under damage conditions, thereby supporting cancer cell survival 2. MAGEA4 expression is upregulated by transcription factors including TWIST1, which binds E-boxes in the MAGEA4 promoter 3. Additionally, a MAGEA4 antisense lncRNA (MAGEA4-AS1) enhances MK2 signaling through p53 interaction, promoting proliferation and metastasis in oral squamous cell carcinoma 4. Clinically, MAGEA4 is highly expressed in multiple solid tumors but minimally expressed in normal tissues except testis and placenta 2. High MAGEA4 expression associates with poor prognosis 2. As a therapeutic target, affinity-enhanced MAGE-A4-specific TCR-engineered autologous T cells (afamitresgene autoleucel) demonstrated clinical efficacy in heavily pre-treated patients with MAGE-A4-expressing synovial sarcoma and myxoid round cell liposarcoma, achieving a 37% overall response rate with acceptable safety 5. These TCR-T cell immunotherapies represent a promising approach for targeting MAGE-A4-positive solid tumors 6.