RBM33 (RNA binding motif protein 33) is an RNA reader protein that regulates RNA metabolism through multiple mechanisms. The protein specifically recognizes and binds N6-methyladenosine (m6A)-containing mRNAs, serving as a molecular adapter that promotes their demethylation by ALKBH5 1. RBM33 facilitates this process by recruiting ALKBH5 to m6A-marked substrates and activating ALKBH5 demethylase activity through recruitment of SENP1, which leads to ALKBH5 deSUMOylation and activation 1. Additionally, RBM33 binds intronless RNAs containing GC-rich elements and promotes their nuclear export by recruiting target RNAs to the NXF1-NXT1 RNA export machinery 1. The protein demonstrates clinical significance in head-neck squamous cell carcinoma (HNSCC), where it promotes tumorigenesis by enhancing autophagy through ALKBH5-mediated demethylation and stabilization of DDIT4 mRNA 1. RBM33 is also involved in abdominal aortic aneurysm pathogenesis, where its circular RNA form (circRBM33) contributes to disease progression through ECM degradation 2. The gene has been identified as a potential obesity susceptibility locus in Northern Han Chinese populations 3.