In this part collection which ranges from part number BBa_K5017000 to BBa_K5017015, we have successfully submitted fifteen basic parts and one composite part to the Registry. The primary function of this collection lies with the Chimeric Antigen Receptor that we constructed (Part:BBa_K5017000). Parts from BBa_K5017001 to BBa_K5017007 are components of this receptor. Parts from BBa_K5017008 to BBa_K5017015 are designed by Dry Lab with the software DiffAb, using a binding optimization algorithm for the anti-MSLN-scFv (Part: BBa_K5017002). We aim to test these optimized sequences in the future in vitro by comparing the strength of antigen-scFv binding, to see if indeed an optimized sequence has better binding properties.