APC-ms are used to precisely control the density of anti-CD3/anti-CD28 presented to a diverse set of T-cell samples representing varying patient health status, including healthy donor T-cells, and T-cells of acute lymphoblastic leukemia (ALL) and chronic lymphocytic lymphoma (CLL) origin, to produce a diverse library of CAR-T cell products. Here, CD28 is linked to B-cell chronic lymphocytic leukemia.