SA2 (STAG2), a core component of the cohesin complex, plays a critical role in maintaining sister chromatid cohesion during mitosis and meiosis, ensuring accurate chromosome segregation. The cohesin complex, composed of SMC1. SMC3. RAD21. and STAG subunits (STAG1/SA1 or STAG2/SA2), also regulates chromatin organization, DNA repair, and gene transcription. SA2 specifically stabilizes cohesin-DNA interactions and facilitates loop extrusion in chromatin architecture. Mutations or dysregulation of SA2 are implicated in genomic instability and cancer, including acute myeloid leukemia (AML), glioblastoma, and bladder cancer, where SA2 loss correlates with aneuploidy and poor prognosis. SA2 antibodies are essential tools for studying cohesin function, detecting protein expression in cells/tissues via techniques like Western blot, immunofluorescence, or ChIP-seq. They aid in exploring SA2's role in chromatin dynamics, mitotic regulation, and disease mechanisms. Research using SA2 antibodies has revealed its tissue-specific expression patterns and potential as a biomarker for cohesinopathies or therapeutic targeting in cohesion-deficient cancers.