TARBP2 is a double-stranded RNA-binding protein with multifaceted roles in viral infection, gene expression, and cancer biology. As a component of the RISC-loading complex, TARBP2 functions in miRNA processing by acting as a Dicer cofactor, though it does not affect Dicer stability or overall miRNA abundance 1. In the context of HIV-1 infection, TARBP2 binds viral TAR RNA and stimulates translation of TAR-containing RNAs partly by inhibiting the kinase PKR, reducing phosphorylation of translation initiation factors 2. Additionally, TARBP2 recruits the FTSJ3 methyltransferase to HIV-1 RNA for 2'-O-methylation, enabling viral immune evasion 3. In innate immunity, TARBP2 negatively regulates interferon-β production by targeting MAVS, thereby suppressing antiviral responses 4. In cancer pathology, TARBP2 exhibits context-dependent roles. Frameshift mutations in TARBP2 impair miRNA processing and destabilize DICER1, promoting microsatellite instability in carcinomas 5. Conversely, TARBP2 overexpression promotes tumor angiogenesis and metastasis by destabilizing antiangiogenic factor mRNAs through 3'UTR binding 6. TARBP2 also drives oncogenic dysregulation by recruiting m6A methylation machinery to pre-mRNAs, promoting intron retention and nuclear exosome-mediated degradation 7. Thus, TARBP2 functions as either tumor suppressor or promoter depending on mutational status and expression level.