EIF4B (eukaryotic translation initiation factor 4B) is a multifunctional RNA-binding protein essential for eukaryotic translation initiation. Its primary function is to promote mRNA ribosome binding by enhancing the helicase activity of EIF4A and working in association with the EIF4F complex 1. EIF4B binds near the 5'-terminal cap of mRNA and stimulates ATP-dependent RNA unwinding, facilitating ribosomal scanning of structured 5' untranslated regions 2. Beyond canonical translation initiation, EIF4B plays roles in translation termination through closed-loop mRNA structures, where it promotes eRF1 loading into the ribosomal A site 3. The protein exhibits expanded regulatory functions, including regulation of histone mRNA stability through interactions with the RNA turnover machinery 2. EIF4B dysregulation contributes to multiple cancers. In breast cancer, YTHDF3 recruits EIF4B to enhance Notch2 translation, driving epithelial-mesenchymal transition and metastasis 4. In pancreatic ductal adenocarcinoma, increased EIF4B phosphorylation via disrupted PP2A signaling elevates global mRNA translation 5. Conversely, genetically proxied EIF4B levels show protective associations with prostate cancer risk 6. Notably, elaiophylin targets EIF4B to suppress esophageal squamous cell carcinoma proliferation via the PI3K/AKT pathway 7, establishing EIF4B as a therapeutic target.