NOS2 and neoplasm: Studies with RT-PCR in samples obtained from the four mouse groups were analyzed for the expression levels of microglia/macrophage and tumor cell-related genes (F4-80, Iba-1, Ki-67, EGR-2, NOS2, and PDL1), metalloprotease-related genes (ADAM 8, 10, and 17, and MMP9 and 14), and metabolic-related genes, such as carbonic anhydrases (CA2, 9, and 12), to represent hypoxia-inducible genes.