Cells of all organisms are equipped with a system for degradation of proteins, the ubiquitin-proteasome system (2004 Nobel Prize in Chemistry). One of its numerous functions is to degrade dispensable cellular proteins and provide building blocks for the generation of essential proteins. The researchers found a way to mislead the cells and to inhibit activation of the proteolytic system during starvation stress, which resulted in their death. The effect is selective to malignant cells which have high metabolic rate and are therefore more sensitive for deficiency in essential building blocks compared with their healthy counterparts.  As the inhibitory compounds are non-toxic natural dietary components, they can be developed into potential novel cancer therapeutic modalities.