XPO5 (exportin 5) is a key component of the microRNA processing machinery responsible for the nuclear export of precursor miRNAs (pre-miRNAs) from the nucleus to the cytoplasm 1. As part of the miRNA biogenesis pathway, XPO5 functions to traffic miRNA hairpins between nucleus and cytoplasm, enabling subsequent processing by DICER1 and loading into the RNA-Induced Silencing Complex (RISC) for gene regulation 1. The protein's nuclear export function is critical for proper miRNA maturation and cellular homeostasis. XPO5 has significant disease relevance, with mutations identified in Wilms tumors alongside other miRNA machinery components including DROSHA, DICER1, and DGCR8 2. In hepatocellular carcinoma, XPO5 undergoes SUMOylation modification that promotes cancer progression by altering pre-miRNA export patterns 3. During SARS-CoV-2 infection, the viral N protein induces autophagic degradation of XPO5, disrupting miRNA biogenesis and contributing to pneumonia severity 4. Genetic variants in XPO5 have been associated with end-stage renal disease susceptibility, though their role in cancer risk remains controversial 56. The protein's central role in miRNA processing makes it a potential therapeutic target for various diseases involving dysregulated gene expression.