HIF-1α downregulates activating ligands, like MICA and MICB, on tumor cells through MMP-mediated shedding [111] and suppresses the expression levels of critical NK activation markers, including NKG2D, NKp30, NKp44, and NKp46 [40], resulting in reduced NK cell cytotoxicity. The gene discussed is KLRK1; the disease is neoplasm.