SF3B2 (splicing factor 3b subunit 2) is a critical component of the U2 small nuclear ribonucleoprotein (snRNP) complex within the spliceosome, functioning as an essential regulator of pre-mRNA splicing 1. As part of the SF3B subcomplex, SF3B2 is required for 'A' complex assembly during spliceosome formation and mediates recognition of the intron branch site during pre-mRNA splicing 1. The protein undergoes post-translational regulation through arginine methylation by PRMT9, specifically at residue R508, which is critical for its splicing function and protein-RNA interactions 2. SF3B2 haploinsufficiency causes craniofacial microsomia (CFM), the second most common congenital facial anomaly, accounting for ~3% of sporadic and ~25% of familial cases 1. Loss-of-function mutations lead to widespread mRNA splicing disruption, elevated apoptosis, and reduced proliferation of cranial neural crest cells, resulting in severe craniofacial developmental defects 3. Clinically, SF3B2 dysregulation is implicated in multiple cancers, including prostate cancer where it drives androgen receptor variant-7 expression and therapeutic resistance 4, and pancreatic cancer where YTHDF1 enhances SF3B2 translation through m6A modification 5. These findings establish SF3B2 as both a developmental regulator and potential therapeutic target.