Synthetic biology can be used to create and improve treatments for many diseases. Genetic techniques are used to modify T cells to create CAR-T cells that can kill some types of cancer cells. Gene therapy offers the promise of curing genetic diseases for which there are no treatments. A significant problem with these technologies is the variability of gene delivery to the targeted cells. Viral particles are often used to deliver the desired genes. A cell could be infected by a single viral particle, or many, meaning the cell could receive one or many copies of the gene to be expressed. The variability in the resulting response of the infected cells means the treatment results could vary widely. The objective of this project is to develop protein circuits that can self-regulate. This would remove the effect of infection variability on cellular performance, and thereby even out the therapeutic effectiveness. The reproducibility this would introduce would accelerate the development process for new biotherapeutic strategies. This project will develop dosage-controlled synthetic circuits by implementing proteolysis-based incoherent feedforward loops (IFFLs). The primary goal is to create self-regulating circuits that maintain consistent performance regardless of delivery variations. The approach combines proteolytic regulation with secreted protein engineering. The research will proceed in two phases: first, establishing the technical foundation using synthetic reporters to dev