SOX2 and neoplasm: However, the distributions of HIF-2α+ cells and SOX2+ HIF-1α+ RNApII-S2P-/low cells were mostly different within peri-necrotic areas (S5C and S5D Fig) as well as within non-necrotic areas (S5E and S5F Fig), suggesting that HIF-2α is expressed in a subpopulation of tumor cells that are mostly different from SOX2+ HIF-1α+ RNApII-S2P-/low cells.