PI3K, or phosphoinositide 3-kinase, is an important enzyme involved in cellular functions such as growth, proliferation, and survival. It plays a crucial role in signaling pathways that help cells respond to various stimuli, including hormones and growth factors. When activated, PI3K converts a specific lipid in the cell membrane, leading to a cascade of reactions that promote cell growth and metabolism. Dysregulation of PI3K signaling is associated with several diseases, including cancer, making it a target for therapeutic interventions.