Phosphatidylinositol 4,5-bisphosphate or PtdIns(4,5)P₂, also known simply as PIP₂, is a minor phospholipid component of cell membranes. PtdIns(4,5)P₂ is enriched at the plasma membrane where it is a substrate for a number of important signaling proteins.

Phosphatidylinositol 4,5-bisphosphate or PtdIns(4,5)P₂, also known simply as PIP₂, is a minor phospholipid component of cell membranes. PtdIns(4,5)P₂ is enriched at the plasma membrane where it is a substrate for a number of important signaling proteins.