NKG2D ligand 2, also known as N2DL-2, NKG2DL2, ALCAN-alpha, Retinoic acid early transcript 1H, UL16-binding protein 2, ULBP2 and N2DL2, is cell membrane protein that belongs to the MHC class I family. ULBP2 / N2DL-2 is expressed in various types of cancer cell lines and in the fetus, but not in normal tissues. ULBP2 / N2DL-2 is a ligand for the NKG2D receptor, together with at least ULBP1 and ULBP3. ULBPs activate multiple signaling pathways in primary NK cells, resulting in the production of cytokines and chemokines. Binding of ULBPs ligands to NKG2D induces calcium mobilization and activation of the JAK2, STAT5, ERK and PI3K kinase/Akt signal transduction pathway.