Figure 1.

Schematic diagram of the main molecular event upon hypoxia. HIF-1α + HIF-1β + HREs would activate the transcription of downstream genes [12]. * FIH: factor inhibiting HIF [13]; ** p300/CBP: p300/CREB binding protein (transcriptional coactivators) [14]; *** HREs: hypoxia-response elements; “↓”: inhibited; “+”: added on