TANK, also known as TRAF interacting protein, is found in the cytoplasm and can bind to TRAF1, TRAF2, or TRAF3, thereby proposing that this protein is an inhibitor of TRAF function that regulates TRAF protein activity by sequestering TRAFs in a latent state in the cytoplasm. Overexpression of TANK inhibits TRAF2-mediated NF-Kappa-B activation signaled by CD40 and both TNF receptors and inhibits LMP1-mediated NF-kappa-B activation by blocking the association of TRAF2 with LMP1. Recombinant human TANK protein, fused to His-tag at N-terminus, was expressed in E.coli and purified by using conventional chromatography techniques.