Thus, NKG2D alone, through the recognition of stress-induced ligands or NKG2D-ligands (NKG2DL) differentially expressed under different cellular stress conditions, can recognize cells suffering from DNA damage, infection, oxidative stress, excessive proliferation or oncogene activation, all markers of cellular stress or malignant transformation, facilitating the immune surveillance [105]. This evidence concerns the gene KLRK1 and infection.