XAGE2 (X antigen family member 2) is a cancer/testis-associated gene located on chromosome X.21-Xp11.22 1. It belongs to the GAGE/PAGE family of tumor antigens 2 and is classified as a cancer/testis/stem (CTS) gene, showing preferential expression in cancer stem-like cells 3. XAGE2 demonstrates selective expression in normal placental tissue, specifically in trophoblast layers throughout pregnancy 4, and has been identified as upregulated in pediatric pancreaticobiliary maljunction (PBM), a condition with high malignant transformation risk 5. The gene shows frequent expression in melanoma metastases and Ewing's sarcoma 1 and is differentially expressed in infective endocarditis patients 6. While XAGE2 was preliminarily identified as progression-related in basal-like breast cancer, subsequent single-cell analysis did not confirm its expression in primary triple-negative breast cancer cells 7. Its protein binding capability suggests potential involvement in cellular interactions [GO annotation]. XAGE2 represents a promising candidate for cancer immunotherapy given its restricted normal tissue expression and cancer-associated upregulation patterns.