VEGFD (vascular endothelial growth factor D) is a growth factor that promotes angiogenesis and lymphangiogenesis by binding and activating VEGFR-2 and VEGFR-3 receptors on endothelial cells 1. VEGFD stimulates endothelial cell proliferation and migration while increasing vascular permeability 1. The protein functions in forming venous and lymphatic vascular systems during embryogenesis and maintains differentiated lymphatic endothelium in adults. In pathological contexts, VEGFD plays a critical role in cancer progression. Tumor-secreted VEGFD promotes lymphangiogenesis in tumor-draining lymph nodes and induces dedifferentiation of high endothelial venules via VEGFR2 signaling, impairing lymphocyte homing and facilitating lymph node metastasis 2. The S100A6 protein upregulates VEGFD expression in lymphatic endothelial cells through the RAGE/NF-κB pathway, promoting lymphatic metastasis in liver cancer 3. SIRT2 modulates VEGFD expression by deacetylating EPAS1, suggesting potential therapeutic targets for inhibiting tumor lymphangiogenesis 4. Beyond vascular biology, VEGFD contributes to neural differentiation, where it functions alongside SDF1α and sFRP1 as a stromal-derived inducing activity factor promoting dopaminergic neuron differentiation from human pluripotent stem cells 5, with potential therapeutic applications for Parkinson's disease.