Oxygen and mammalian cell culture: are we repeating the experiment of Dr. Ox?

Mammalian cell culture represents a cornerstone of modern biomedical research. There is growing appreciation that the media conditions in which cells are cultured can profoundly influence the observed biology and reproducibility. Here, we consider a key but often ignored variable, oxygen, and review why being mindful of this environmental parameter is so important in the design and interpretation of cell culture studies.