KLRK1 and neoplasm: Moreover, it can also serve as a ligand of NKG2D, which can activate the human immune system to kill tumors and avoid damaging the normal tissues of the body.23 PHLPP2, a kind of phosphatases rich in leucines, is a member of protein phosphatase PHLPP and an important regulator of protein kinase B (AKT), which can dephosphorylate AKT and thus inhibit tumor development.