Fms-related tyrosine kinase 4, also known as FLT4, is a protein which in humans is encoded by the FLT4 gene.
This gene encodes a tyrosine kinase receptor for vascular endothelial growth factors C and D. The protein is thought to be involved in lymphangiogenesis and maintenance of the lymphatic endothelium. Mutations in this gene cause hereditary lymphedema type IA.