CD40 ligand, also known as CD40LG, is a member of the TNF superfamily and is expressed on activated T cells. CD40LG is expressed as a soluble cytokine as well as a homotrimeric type II transmembrane protein. It has been reported to be important for B cell costimulation following binding of its receptor, CD40. Mutations in the gene encoding for CD154 are implicated in hyper-IgM immunodeficiency syndrome type 1. Recombinant human CD40LG protein, fused to His-tag at N-terminus, was expressed in E.coli and purified by using conventional chromatography techniques. Synonyms: CD40 ligand, CD154, CD40L, gp39, hCD40L, HIGM1, IGM, IMD3, T-BAM, TNFSF5, TRAP. NCBI no.: NP_000065