Warburg reportedly described cancer cells as having several differences when compared with healthy cells. First, cancer cells tend to be slightly acidic when compared with healthy cells that are slightly alkaline. Second, cancer cells are anaerobic, while healthy cells are aerobic (and use oxygen effectively in the metabolism process of generating energy that is stored as ATP). Third, cancer cells are “glucose hogs,” using 10-20 times more glucose than healthy cells. Fourth, cancer cells can rewire themselves to create energy using glucose—a rather energy-intensive way to generate energy—even when mitochondria (energy factories in the nucleus of healthy cells) are present.