HIF1A and breast cancer: Studies have shown that MYC is involved in the regulation of HIF1α expression: the overexpression of MYC can significantly improve the stability of HIF1α protein in breast cancer cells under normoxia and hypoxia; through post-transcriptional regulation, the overexpression of c-Myc can increase the expression of HIF1α in colorectal cancer; inhibition the expression of c-Myc in glioblastoma multiforme cells can down-regulate HIF1α transcription and reduce glycolysis (26–28).