CTSG and immunodeficiency disease: NOD/SCID mice with IL2rg mutations, such as NOD.Cg-PrkdcscidIl2rgtm1Wjl (NSG) or NODShi.Cg-PrkdcscidIl2rgtm1Sug (NOG) mice, have highly enhanced immunodeficiency and are able to engraft almost all types of human cancers [39].