HIF1A and neoplasm: Furthermore, hypoxic tumor cells, via HIF-1α, can upregulate the expression of the metalloproteinase ADAM10, which is responsible for the shedding of the natural killer group 2, member D (NKG2D) ligand major histocompatibility complex (MHC) class I chain-related molecule A (MICA) from the tumor cell surface [28].