Cells need energy to survive and thrive. Generally, if oxygen is available, cells will oxidize glucose to carbon dioxide, which is very efficient, much like burning gasoline in your car. However, even in the presence of adequate oxygen, many malignant cells choose instead to ferment glucose to lactic acid, which is a much less efficient process. This metabolic adaptation is referred to as the Warburg Effect, as it was first described by Otto Warburg almost a century ago. Ever since, the conditions that would evolutionarily select for cells to exhibit a Warburg Effect have been in debate, as it is much less efficient and produces toxic waste products.