We demonstrate that CD133+ LMPCs that are podoplanin+/VEGFR-3+/CD31−, as well as CD133− LMECs that are podoplanin+/VEGFR-3+/CD31+, develop ectatic aberrant lymphatics that phenocopy the lymphatic vessel morphology in LM tissues. This evidence concerns the gene FLT4 and lymphangioma.