Hypoxia leads to release of Myc from the CDKN2B promoter. ChIP experiments were performed on extracts from U2OS cells using an antibody (Ab) against Myc or preimmune IgG as indicated. The cells were cultured at normoxia (21% O2) or at hypoxia (1% O2) for 4 or 24 hours before harvested. qPCR was performed with primers spanning the proximal (−168/-19) (A, left panel) or distal (−3874/-3744) (A, right panel) CDKN2B promoter sequences, and primers spanning either the proximal (+6/+106) (B, left panel)) or distal (−2337 /-2158) (B, right panel) CDKN1A promoter sequences. The results are given as average enrichment of the indicated promoter fragment +/− stdev, n = 6. Statistical analyses: ANOVA (Dunnett’s T3), **P ≤ 0.01, *P ≤ 0.05, ns: not significant. For the IgG control experiments there were no statistically significant differences detected, apart from on the CDKN2B distal promoter, as indicated in the figure (A, right panel).