SSX3 is an X-linked member of the SSX gene family, a group of cancer-testis antigens normally expressed in testis and thyroid 1. The protein contains a Krüppel-associated box (KRAB) domain and localizes to the nucleus, where it likely functions as a transcriptional modulator 21. SSX3 shares 90-95% sequence homology with other SSX family members and can interact with nuclear proteins such as SSX2IP, suggesting involvement in protein-protein interaction networks 1. Unlike SSX1 and SSX2, SSX3 does not act as a fusion partner with SYT in synovial sarcoma 2. Clinically, SSX3 has emerged as a candidate gene in nonobstructive azoospermia, suggesting involvement in spermatogenesis 3. SSX3 expression has been detected in certain malignancies, including sarcomas and potentially colorectal cancer, where its expression can be induced by epigenetic modulators 45. A novel EWSR1-SSX3 fusion has been identified in undifferentiated bone sarcomas, indicating potential oncogenic roles 5. Unlike other SSX family members, SSX3 expression cannot be induced by DNA methyltransferase inhibitors or histone deacetylase inhibitors in certain cell contexts, suggesting alternative regulatory mechanisms 6.