The primary function of signaling pathways in cells is to transmit information necessary for cellular responses to external stimuli. These pathways regulate a variety of processes, including cell growth, differentiation, and apoptosis. Signaling molecules, such as hormones and neurotransmitters, bind to receptors, initiating cascades of interactions that ultimately lead to specific cellular outcomes. Proper functioning of signaling pathways is essential for maintaining homeostasis and responding to environmental changes.