HIF1A and cancer: In this sense, several agents, already approved for cancer treatment, affect the rate of HIF-1 protein synthesis, including receptor tyrosine kinase inhibitors, cyclin-dependent kinase inhibitors, p53 activators, and also other approved therapies like the inhibitors of topoisomerase I and II, such as topotecan, EZN-2208, and microtubule-disrupting agents [113,114,115].