CD40 and its crucial role as a member of the TNFR family

The cell surface molecule CD40 is a member of the tumor necrosis factor rec eptor (TNFR) family and plays a pivotal role in the immune system due in pa rt to its wide tissue distribution. Early studies focused on CD40 in B cell biology, but recent work demonstrates a broader role for CD40 in the immun e system contributing to cell-mediated as well as humoral immune responses. Disruption of CD40 and its ligand, CD154 leads to immunodeficiency as in t he case of hyper IgM syndrome. Likewise, blockade of CD40-CD154 interaction s can be exploited to control misguided autoimmune responses. This article provides a brief overview of CD40 with a focus on its involvement in diseas e and its usefulness as a therapeutic target.