Correspondingly, hypoxia has also been reported to increase the shedding [203] or downregulate the expression of an NKG2D ligand, the major histocompatibility complex (MHC) class I polypeptide-related sequence A (MICA), which correlates with a decreased susceptibility of tumor cells to NK cell-mediated cytotoxicity [204]. This evidence concerns the gene MICA and neoplasm.