Musashi-2 (MSI2): a central node connecting RNA regulation, disease pathogenesis, and targeted therapeutics

RNA-binding proteins are increasingly recognized as major determinants of gene regulation in physiology and disease, yet how individual post-transcriptional regulators connect RNA control to cell-state transitions and therapeutic vulnerability remains incompletely understood. Musashi-2 (MSI2), a member of the evolutionarily conserved Musashi family, has emerged as a central regulator of RNA fate across diverse biological systems. Initially characterized in stem and progenitor cell compartments, MSI2 is now implicated in a broad spectrum of hematological malignancies, solid tumors, and selected non-neoplastic disorders. Here, we synthesize current knowledge of MSI2 from molecular architecture to disease relevance and translational potential. We discuss how MSI2 regulates mRNA stability, translation, alternative splicing, and, in selected contexts, non-coding RNA processing, thereby influencing stemness, differentiation blockade, proliferative fitness, stress adaptation, epithelial–mesenchymal transition, metastasis, and therapy resistance. Across disease systems, MSI2 recurrently functions as a post-transcriptional hub that stabilizes pathogenic cellular states; however, its biological output is highly context dependent and shaped by lineage identity, target transcript repertoire, interacting cofactors, upstream regulatory circuitry, and environmental stress. We further examine the emerging translational landscape of MSI2, including its potential as a biomarker of aggressive and treatment-adapted disease states, as well as current efforts to therapeutically target MSI2 directly or indirectly. Altogether MSI2 represents a compelling node for intervention, major challenges remain, including structural tractability, context-specific dependency, potential toxicity in normal stem cell compartments, and compensation within broader RNA regulatory networks. Together, current evidence positions MSI2 as an important conceptual and therapeutic entry point into post-transcriptional disease biology. Rather than functioning as a universal oncogenic switch, MSI2 is best understood as a context-responsive post-transcriptional organizer through which diverse pathological states are established, maintained, and potentially therapeutically destabilized.