Protein signaling is a field of research that focuses on the intricate communication network within cells that is mediated by proteins. Proteins play a crucial role in transmitting signals from the extracellular environment into the cell, leading to a variety of cellular responses such as growth, division, differentiation, and apoptosis. This signaling process involves a complex network of interactions between different proteins, including receptors, enzymes, and transcription factors. Understanding protein signaling pathways is important for elucidating the mechanisms underlying various physiological and pathological processes, and it has implications for the development of targeted therapies for diseases such as cancer and metabolic disorders.