MDK and nasopharyngeal carcinoma: For example, Lu et al. unearth that exosomes secreted by nasopharyngeal carcinoma cells can be absorbed by vascular endothelial cells, in which miR-9 targets MDK of the recipient cells and regulates the PDK/AKT pathway to inhibit angiogenesis, thereby inhibiting the metastasis of nasopharyngeal carcinoma [23].