Phosphatidylinositol 4,5-bisphosphate (PIP2) is a critical phospholipid that plays a pivotal role in cell signaling pathways, particularly in the regulation of actin cytoskeleton dynamics and membrane trafficking. It serves as a precursor for secondary messengers like inositol trisphosphate (IP3) and diacylglycerol (DAG), which are essential for various cellular processes including calcium signaling and protein kinase C activation.