In patients with cancer, NKG2D generally binds specifically to killer cell lectin-like receptor subfamily K, member 1 ligands (NKG2DLs) expressed on transformed malignant cells, such as MHC class I-related molecules, MHC class I polypeptide-related sequence A/B (MICA/MICB), and UL16-binding protein (ULBP) [30]. The gene discussed is KLRK1; the disease is cancer.