Receptor biology is a branch of biology that focuses on studying the molecular mechanisms of how cells receive and respond to signals from their environment. Receptors are proteins located on the surface of cells or within the cell that bind specific molecules, such as hormones, neurotransmitters, or growth factors. Upon binding to their ligands, receptors initiate a cascade of signaling events within the cell that ultimately lead to changes in cellular function, gene expression, or behavior. Research in receptor biology often involves studying the structure, function, and regulation of receptors, as well as their role in various physiological and pathological processes. Understanding receptor biology is crucial for developing new therapeutic strategies for a wide range of diseases, including cancer, diabetes, and neurological disorders.