Immune receptors are surprisingly modular and can be mutated and composed to rewire cellular inputs and outputs, as showcased by the success of cell-based genetic therapies like Chimeric Antigen Receptor T-cell (CAR-T) therapy. My work involves high-throughput pooled screening of thousands of different synthetic receptors. A better understanding of the relationship between receptor sequence, signaling outcome, and cellular phenotype will lead to next-generation cell-based genetic therapies which manipulate the immune system to combat a variety of diseases.