4-1BB ligand

4-1BB is a type 2 transmembrane glycoprotein receptor belonging to the TNF superfamily, expressed on activated T Lymphocytes. 4-1BB is a type 2 transmembrane glycoprotein receptor belonging to the TNF superfamily, expressed on activated T Lymphocytes. 4-1BBL (4-1BB ligand) is found on APCs (antigen presenting cells) and binds to 4-1BB.