Although breast cancer cells have heterogeneous properties, all of them have a high nutritional demand. The activity of the enzyme Gcn2 is important to meet this demand, thereby supporting cancer cell survival and growth. We have found that Gcn2 activity is critically dependent on a unique protein-protein interaction (PPI). Our hypothesis is that a drug could specifically disrupt this PPI, prevent Gcn2 activation, and thereby provide an effective treatment for virtually all breast cancer types with minimal side effects. To test this, we will conduct protein structure modelling, biochemical and genetic studies, to design and characterise peptides for their potency in disrupting the PPI and inhibiting Gcn2 activation. The most potent peptides will be tested for their efficacy in impairing breast cancer cell growth. These peptides will inform the development of PPI-disrupting drugs that promise to improve the treatment for many breast cancer patients, increasing their quality of life and improving survivorship.