NCIt definition : Proteins that regulate transcription via interaction with chromatin and basal transcription
machinery at the promoter regions of genes. Nuclear receptors are ligand-dependent
transcription factors including steroids, retinoids, vitamin D, unliganded thyroid
hormone, and orphan receptors (unknown ligands). Coregulators (coactivators or corepressors)
are important in mediating these interactions and thereby modulate positive or negative
receptor activity.;