Table 3.

Molecular aspect of vascular anomalies.

Diseases	Causative Genes	Possible Function
Venous malformation	TIE2, PIK3CA, Akt	Affect cytokine expression, resulting in misguiding of smooth muscle cells to the surroundings of blood vessels and leading to abnormal venous dilation Induce both proliferation and senescence of endothelial cells, which leads to morphological abnormalities
Glomuvenous malformation	Glomulin	Inhibit TGF-β-mediated smooth muscle cell differentiation and induce the proliferation of immature glomus cells Activate PI3K signals through interactions with c-met
Lymphatic malformation	PIK3CA	Stimulate cytokine expression Induce the binding of PIK3CA to the cellular membrane, or increase endothelial cell proliferation, chemotaxis, and angiogenesis
Arteriovenous malformation	RAS	Induce morphological changes in endothelial cells Induce sprouting behavior, enlargement of the vessel lumen, and abnormal connections between arteries and veins
Klippel-Trenaunay syndrome	PIK3CA	Mosaic mutations in the early embryonic phase cause segmental hypergrowth
Capillary malformation Sturge-Weber syndrome	GNAQ, GNA11	Impair the ability of endothelial cells to distinguish between laminar and disturbed flow Activate the PIK3/Akt pathway
Infantile hemangioma	VEGFR2 TEM8, etc.	Increase the interaction among VEGFR2, TEM8 and integrin Subsequent inactivation of the integrin-NFATc2-VEGFR1 pathway cause VEGFR2 phosphorylation and endothelial activation
Tufted angioma Kaposiform hemangioendothelioma	GNA14	?