Cell signaling is the process by which cells communicate with one another to coordinate various physiological functions, such as growth, development, and response to external stimuli. Cells use a variety of signaling molecules, including hormones, neurotransmitters, and growth factors, as well as receptor proteins on their cell membranes, to transmit signals from the extracellular environment to the interior of the cell. This signaling process plays a crucial role in regulating cellular activities and maintaining tissue homeostasis, and abnormalities in cell signaling pathways can lead to various diseases such as cancer, diabetes, and neurodegenerative disorders. Research in cell signaling aims to understand the mechanisms underlying these signaling pathways and develop new therapeutic strategies for treating diseases associated with aberrant cell signaling.