KLRK1 and cancer: The NK cell-activating receptor NKG2D (CD314) recognizes MHC class-I-chain related proteins A and B (MICA and MICB) and ULBPs (1–6), while DNAM-1 binds to CD112 (Nectin-2) and CD155 (poliovirus receptor) (5) on stressed, infected, and cancer cells.