Biological signaling is the process by which cells communicate with each other to coordinate their activities. This communication is typically carried out through various signaling molecules, such as hormones, neurotransmitters, and growth factors, which bind to specific receptors on the surface of cells. The activation of these receptors triggers a signaling cascade within the cell, leading to specific responses such as changes in gene expression, cell proliferation, differentiation, or apoptosis. Understanding biological signaling is crucial for elucidating the mechanisms underlying various physiological and pathological processes, and for developing new therapeutic strategies for a wide range of diseases.