Mitogen-Activated Protein Kinases (MAPKs) are a group of proteins that play a crucial role in transmitting signals within cells. They are activated by various stimuli, such as growth factors, stress, and cytokines, and are involved in regulating essential cellular processes like growth, differentiation, and apoptosis. There are several types of MAPKs, including ERK, JNK, and p38, each with specific functions and pathways. These kinases work in a cascade, where one kinase activates another, leading to a coordinated cellular response. Understanding MAPKs is important for developing therapies for diseases like cancer and inflammatory disorders.