CD70 is a type II transmembrane glycoprotein and a member of the tumor necrosis factor ligand superfamily (TNFSF), also known as CD27L and TNFSF7. It is normally expressed on medullary thymic epithelial cells. Its expression is induced on activated lymphoid cells (B cells, T cells, and NK cells) and dendritic cells. CD70 is a ligand for CD27, a co-stimulatory receptor that plays an important role in T cell activation and proliferation. CD70 overexpression has been reported in various tumors such as renal cell carcinoma, glioblastoma, and non-small cell lung carcinoma and it’s being actively pursued as a therapeutic target.