SSX2 is a chrX-associated transcriptional regulator normally expressed only in testis and thyroid, but aberrantly expressed in various cancers 1. The protein functions as a DNA-binding protein that antagonizes polycomb group (PcG) complexes by disrupting BMI1 and EZH2 PcG body formation and derepressing PcG target genes 2. SSX2 binds double-stranded DNA in a sequence non-specific manner and negatively regulates H3K27me3 histone marks, suggesting it modulates chrX structure indirectly rather than affecting PcG complex composition 2. The protein localizes to the nucleus and promotes formation of novel intranuclear lamin bodies containing A and B type lamins, which is dependent on S-phase progression 3. SSX2 interacts with specific proteins including RAB3IP and SSX2IP through its N-terminal domain 1. In cancer contexts, SSX2 is involved in the pathognomonic t(X;18) translocation creating SYT-SSX2 fusion proteins in synovial sarcoma 45, where it regulates apoptotic pathways by increasing BCL2 while repressing MCL1 and BCL2A1 6. SSX2 serves as a tumor-associated antigen target for cancer immunotherapy approaches 7.