BEX1 (brain expressed X-linked 1) is a signaling adapter molecule with context-dependent roles in cell proliferation, differentiation, and disease. Normally expressed in brain, pancreas, testis, and ovary 1, BEX1 functions in p75NTR/NGFR signaling and coordinates cell cycle progression with neuronal differentiation [UniProt]. However, dysregulation of BEX1 drives multiple cancer pathways. In hepatoblastoma and cancer stem cell-enriched hepatocellular carcinoma, DNMT1-mediated methylation silences BEX1; its reactivation promotes stemness by blocking RUNX3-mediated inhibition of Wnt/β-catenin signaling 2. BEX1 further sustains hepatoblastoma stemness through PPARγ/PDK1-dependent enhancement of the Warburg effect 3. In gliomas, BEX1 suppression via promoter methylation paradoxically activates pro-tumorigenic AKT/ERK/STAT3 signaling 4, while in glioblastoma survivors post-radiotherapy, BEX1 upregulation promotes actin polymerization and YAP/TAZ activation, enhancing radioresistance 5. Conversely, BEX1 displays cardioprotective antiviral functions during coxsackievirus infection by limiting viral replication and regulating interferon-beta expression 6, though it also amplifies pathological proinflammatory gene expression during heart failure by stabilizing AU-rich element-containing mRNAs 7. These findings establish BEX1 as a pleiotropic regulator with therapeutic implications across cancer and cardiovascular disease.