Signaling between cells in physical contact.
Cell signaling is the complex process by which cells perceive and respond to their environment. It is essential for homeostasis, growth, and immune responses.
Common transducers include G-protein coupled receptors (GPCRs) , which use secondary messengers like cyclic AMP (cAMP) to amplify signals. 2. Signaling Theory (Economics & Management) Signaling Theory: A Review and Assessment - Sage Journals
Nearby cells are targeted (e.g., neurotransmitters).
Long-distance signaling via the bloodstream (e.g., hormones).