Tumor necrosis factor Receptor 1(TNFRI), also known as tumor necrosis factor receptor Superfamily member 1A(TNFRSF1A) and CD120a, is a member of the tumor necrosis factor receptor superfamily. It activates the transcription factor NF-κB, mediates apoptosis and regulates inflammation. Mutations in the TNFRI gene have been linked to an increased risk of multiple sclerosis. Serum levels of TNFRI are elevated in patients with schizophrenia and bipolar disorder, and high levels of TNFRI are associated with more severe psychotic symptoms.