Phosphoinositide 3-kinases (PI3Ks) were a family of enzymes that phosphorylated the 3′-OH position of the inositol ring of phosphatidylinositol (PI), and regulated signaling pathways.[13] For example, the class I PI3K, p110β impaired platelet activation and prevented the formation of arterial thrombosis.[14,15] In contrast to the class I PI3Ks, the roles of the class II PI3Ks (PI3KC2α, -C2β, and -C2γ) remained unknown. The gene discussed is PIK3C2A; the disease is deep vein thrombosis.