Signaling pathway

A signaling pathway is a coordinated series of chemical reactions and molecular interactions through which a cell converts a specific stimulus, such as a hormone or growth factor, into a functional response (National Cancer Institute). These pathways typically involve a sequence of events starting with ligand-receptor binding, followed by the activation of intracellular transducers and effectors that ultimately regulate gene expression or cellular behavior (Nature Education). In the context of drug discovery, a 'signaling pathway' is considered an abstract biological process or category rather than a discrete molecular target; pharmacotherapy instead focuses on modulating specific components within these pathways, such as kinases, ion channels, or G protein-coupled receptors (Molecular Biology of the Cell). Dysregulation of these signaling cascades is a fundamental driver of human disease, particularly in oncology where aberrant activation promotes uncontrolled cell proliferation and survival (PubMed). Because pathways involve numerous interacting proteins, targeting a 'pathway' as a whole is conceptually common, but the physical interaction of a drug always occurs with a specific molecular target within that system.

Other names

Signal transduction pathwayCell signaling cascadeIntracellular signaling pathwayBiochemical signaling network

Not applicable; signaling pathways represent complex biological systems or series of events rather than a single druggable molecular entity.