Phosphatidylinositol 3-phosphate
Phosphatidylinositol 3-phosphate (PI3P) is a phospholipid found in cell membranes that helps to recruit a range of proteins, many of which are involved in protein trafficking, to the membranes. It is the product of both the class II and III phosphoinositide 3-kinases (PI 3-kinases) activity on phosphatidylinositol.
Source: Wikipedia — Phosphatidylinositol 3-phosphate (CC BY-SA 4.0)