Nuclear receptors are a family of ligand-regulated transcription factors with important physiological functions. These receptors are located in the cytoplasm or the nucleus of the cell. Nuclear receptors are classified as transcription factors due to their ability to bind directly to DNA and regulate the expression of adjacent genes. They are a class of proteins responsible for sensing steroids, hormones, vitamins, and certain other molecules. By modulating the expression of specific genes involved in various cellular functions, these transcription factors mediate the effects of small molecule drugs, hormones, and other xenobiotics. They play an important role in embryonic development and adult homeostasis while influencing a wide variety of functions including fatty acid metabolism and detoxification of foreign substances.