CD30, also known as Ki-1 antigen, lymphoid activation antigen CD30, and tumor necrosis factor receptor superfamily member 8 is a type I transmembrane receptor that contains four TNF receptor domains with an approximate molecular weight of 64 kD. CD30 is highly expressed on Hodgkins and Reed-Sternberg cells as well as activated, but not resting, T and B cells. CD30 has been shown to interact with a number of proteins including TRAF1, TRAF2, TRAF3, TRAF5, NPM-ALK, TRAF-interacting protein, and CD30 ligand (CD153). Signaling through CD30 is thought to limit the proliferative potential of autoreactive CD8 effector T cells and protect against autoimmunity.