Protein kinase C (PKC) is a family of enzymes that play a crucial role in cellular signaling. These enzymes are activated by various signals, including growth factors and hormones, and are involved in regulating several cellular processes such as cell growth, differentiation, and apoptosis (programmed cell death). PKC is known to be involved in the response to diacylglycerol (DAG) and calcium ions, which are important signaling molecules. There are several isoforms of PKC, each with specific functions and tissue distributions, making them essential for maintaining normal cellular functions and responding to external stimuli.