CD70, also named CD27 ligand (CD27L), is a type II transmembrane glycoprotein belonging to the TNF superfamily (TNFSF) and has been designated TNFSF7.? CD70 is a cytokine that binds to CD27. Plays a role in T-cell activation. Induces the proliferation of costimulated T-cells and enhances the generation of cytolytic T-cells.