[3H]Thymidine incorporation assay clearly showed that SphK1-silenced A498 and 786-O cells proliferated much slower than their siScr-silenced counterparts (Figure 3d, left) and showed a survival disadvantage (Figure 3d, right) in both normoxia and hypoxia in line with the findings that HIF-2α likely contributes to tumor cell survival.39 This evidence concerns the gene EPAS1 and neoplasm.