In paracrine signaling, the signaling molecules bind to and stimulate nearby cells. It is one of the four types of extracellular cell signaling found within multicellular organisms. The other three types of cell signaling are endocrine, neuronal (synaptic) and juxtacrine (signaling by cell contact).
Paracrine signaling molecules are released from specialized paracrine cells. The molecules do not have the ability to enter the bloodstream to travel the entire body as endocrine signaling molecules do. Therefore, paracrine molecules must diffuse only locally through the organism's extracellular fluid to target nearby cell receptors. Paracrine signaling molecules act as a local mediator in many cell functions, such as inflammatory response and cell proliferation.