Engineering immune cells to target disease antigens is a promising therapeutic modality, particularly in the fight against cancer. Chimeric Antigen Receptor (CAR) expressing T-cells have been demonstrated as an effective adoptive cell therapy for liquid cancers. Significant challenges remain for treating solid tumors with CAR-T therapies, including toxicity, activation within tumors, and persistence in vivo. These challenges underscore a clear need for the innovation of new CARs. To aid in this effort, Twist Bioscience offers a suite of protein engineering tools for researchers to rapidly advance through the design and test phases of their CAR research pipeline.