Expression profiles of hypoxia-related tissue factors were as follows: HIF-2α and FGFR expression was detectable only in a minority of cells, while VHL and CA IX were consistently expressed in the context of CD117 positive vital tumor tissue (Fig. 1C–G); in the same areas, immunolabeling with the C-terminus of the p145 human c-kit protein was negative. This evidence concerns the gene CA9 and neoplasm.