HIF1A and cancer: HIF-1α and HIF-2α are responsible for the transcriptional activity of some genes involved in the maintenance and evolution of cancer stem cells (CSCs), such as POU domain, class 5, transcription factor 1 (POU5F1) [82], delta-like 1 Homologue (DLK1) [83], CD133 [84], and CD24 [85].