Given our results, we next determined if HIF-mediated regulation of KDM2 was occurring at the promoter level. Bioinformatic analysis of the KDM2A and KDM2B promoters revealed putative hypoxia response elements (HREs) in both promoters, some quite close to the transcriptional start site (Figure 5A, Figure S5). We thus designed primer sets for the putative HRE sites present in the KDM2A and KDM2B promoters nearer the transcription start and performed chromatin immunoprecipitation (ChIP) analysis in hypoxia, for the levels of HIF-1α and HIF-1β present at these sites using qPCR (Figure 5A). We could detect significant levels of both HIF-1α and HIF-1β present at the KDM2A promoter when cells were exposed to hypoxia (Figure 5A). Interestingly, HIF-1α and HIF-1β were also present at the KDM2B promoter, under the same conditions.