Nur77 (also known as NR4A1) is a nuclear receptor in the NR4A subfamily that regulates gene expression without the need for ligand activation. It is widely expressed in various cells and tissues, such as neuronal cells, immune cells, and myocardial cells, involved in regulating cell proliferation, differentiation, apoptosis, and metabolism. Nur77 activates or inhibits the expression of downstream genes by recognizing and binding to specific DNA sequences. Its activity is regulated by multiple signaling pathways, such as PKA and PKC pathways. Dysregulation of Nur77 expression is associated with the development of various diseases, including cancer, cardiovascular diseases, and autoimmune diseases.