Recent studies of families with hereditary forms of lymphedema have identified 13 genes associated with the development of primary lymphedema: FLT4 (VEGFR3), GJC2, FOXC2, SOX18, GATA2, CCBE1, PTPN14, KIF1, VEGFC, HGF, MET, PIEZO1, and EPHB4 [2,3,4,5]. Here, FLT4 is linked to primary lymphedema.