EIF3I (eukaryotic translation initiation factor 3 subunit I) is a 36-kDa WD40 domain-containing protein and core component of the eIF3 complex essential for translation initiation 1. As part of the eIF3 complex, EIF3I facilitates recruitment of initiation factors to the 40S ribosome, mRNA scanning, and AUG recognition during formation of the 43S pre-initiation complex 2. Beyond canonical translation initiation, EIF3I exhibits selective translational regulation of specific mRNAs involved in cell proliferation and differentiation 3. EIF3I is frequently overexpressed in multiple cancers and functions as an oncogene through both canonical and noncanonical mechanisms 1. In hepatocellular carcinoma, overexpressed EIF3I directly interacts with and activates Akt1 kinase, preventing PP2A-mediated dephosphorylation and establishing constitutively active oncogenic signaling 4. In colorectal cancer, EIF3I promotes cell survival by augmenting PHGDH translation, facilitating metabolic reprogramming 5, and drives metastasis through selective translation of NELFCD to promote EMT and invadopodia formation 6. EIF3I overexpression correlates with poor prognosis and represents a therapeutic target, as Akt1 inhibitors can suppress EIF3I-mediated tumorigenesis 4. Additionally, EIF3I can bind TGF-β signaling components and regulate Wnt/β-catenin pathway components, implicating broader roles in signal transduction 1.