SF3B6 is a core component of the 17S U2 snRNP complex within the spliceosome, essential for removing introns from pre-mRNAs 1. As part of the SF3B subcomplex, SF3B6 participates in early spliceosome assembly and mediates branch site recognition by directly contacting the intron branch-site adenosine, the nucleophile for the first catalytic splicing step 2. SF3B6 stabilizes the branch site-U2 snRNA duplex, enhancing intron binding even with poor sequence complementarity 3. Structurally, SF3B6 promotes functionally relevant conformational transitions in SF3B1 through enhanced residue motions and acts as a potential allosteric regulator for branch point selection and alternative splicing 4. Beyond canonical splicing, SF3B6 participates in minor spliceosome function for U12-type intron splicing 5. Clinically, SF3B6 is implicated in cancer development, with studies in breast and pancreatic cancers demonstrating that SF3B6 promotes oncogenic phenotypes through regulation of alternative splicing and gene expression, affecting pathways including NF-κB signaling and metabolic processes 67. Additionally, SF3B6 has been identified as a potential biomarker differentiating psoriatic arthritis from psoriasis 8.