HIFs IN CANCER PROGRESSION.  (Semenza.  PDF)
This is from an excellent paper, with several exceptions, by Jeff Semenza MD, on hypoxia.  The text in brackets is mine.  

HIFs play key roles in many crucial aspects of cancer biology including 1. angiogenesis, (the growth of blood vessels to accommodate the growth of a tumour) 2. stem cell maintenance, (preventing the cell from fully differentiating to a mature cell going onto terminal differentiation, ie apoptosis or cell suicide) 3. metabolic reprogramming (from oxidative metabolism to non oxidative fermentation of glucose), 4. autocrine growth factor signalling (self signalling rather than paracrine {from cells next door}, juxtacrine {close by}, or endocrine {distant} signalling, 5. epithelial-mesenchymal transition or EMT (not limited to a single or monolayer of cells, eg those lining a milk duct and conversion of resultant tumor cells from an epithelial phenotype to a mesenchymal phenotype), 6. invasion (of surrounding tissue), 7.  metastasis (cells moving into nearby bloodvessels then circulating to set up a secondary tumor at a a distant site), and  8. resistance to radiation therapy and chemotherapy.

AMAZING!!!
ALL attributes of CANCER, built into almost every cell in response to HYPOXIA.  WHY?  Why don't cancer researchers ask this question? This and a lot of other factors suggest 'wild type' cancer.    There is one very important word glaringly missing in this paper.  DEDIFFERENTIATION of the cancer cell, going BACKWARDS, retracing the steps that it took during embryogenesis.  Older books eg my 'Ocology 1972' are full of the word.  It is not questioned.  It is a word that has fallen into almost total misuse, maybe for the very reason that is might suggest Larmarkism, ie back all the way to the germ line and THAT is heresy. (This blindness seems to coincide with the rise of Richard Dawkins).  Thus the stem cells referred to might have arisen from fully differentiated cells that have dedifferentiated in response to hypoxia.  

Instead of the paper suggesting addressing the CAUSES of the hypoxia, ie stress and arteriosclerosis it instead suggests different sites whereby the action of HIF's might be blocked by a drug or two or three.  Still, getting rid of the stress in the US, might make these drugs, and their myriad side effects, the only option.  (I live in Australia.)