XPO5, also known as Exportin 5, is a key protein in the miRNA biogenesis pathway. It mediates the nuclear export of precursor pre-miRNA to the cytoplasm in a RanGTP-dependent manner, which is crucial for the maturation of miRNAs that play vital roles in gene expression regulation and cell homeostasis [1,2].

Genetic deletion of XPO5 in mouse models compromises the biogenesis of most miRNAs, leading to severe defects during mouse embryonic development and skin morphogenesis, revealing its essential role in these biological processes [2]. In addition, in vitro studies show that knockdown of XPO5 in head and neck cancer cells decreases cell proliferation, delays wound healing, and increases caspase-3 enzyme activity, indicating its oncogenic potential in head and neck squamous cell carcinoma (HNSCC) [3].

In conclusion, XPO5 is essential for miRNA biogenesis and plays important roles in various biological processes such as embryonic development and skin morphogenesis. Its dysregulation is associated with diseases like HNSCC. The study of XPO5 knockout or knockdown models has provided valuable insights into its functions and its implications in disease, offering potential directions for biomarker discovery and therapeutic target identification.