SF3A2 is a core component of the 17S U2 snRNP complex within the spliceosome, which removes introns from pre-mRNAs 12. As part of the SF3A subcomplex, SF3A2 participates in early spliceosomal assembly and branch site recognition by promoting selection of the branch-site adenosine during the first catalytic step of splicing 123. SF3A2 directly interacts with the U2 snRNA-intron duplex and is involved in pre-catalytic spliceosome assembly, including Bact and A complexes 45. Beyond canonical splicing functions, SF3A2 has non-canonical roles in mitotic chromosome 19 through direct binding to spindle microtubules and the Ndc80 kinetochore complex 6. Clinically, SF3A2 is elevated in multiple cancers including triple-negative breast cancer and colorectal cancer, where it promotes tumor progression and regulates alternative splicing of oncogenic targets 78. In breast cancer, SF3A2 mediates cisplatin resistance through apoptosis regulation 7. Post-translational modifications, including acetylation at lysine 10, modulate SF3A2 function in cardioprotection 9. These findings identify SF3A2 as a potential therapeutic target across multiple diseases.