Figure 6 Lymphocytes from colorectal cancer patient No 3 were grafted with an anti‐carcinoembryonic antigen (CEA) receptor with combined CD3ζ and CD28 signalling domains. (A) Schematic diagram of the expression cassettes for the recombinant BW431/26‐scFv‐Fc‐ζ receptor (#439) with CD3ζ signalling domain and the BW431/26‐scFv‐Fc‐CD28‐ζ.receptor (#607) with the combined CD3ζ and CD28 signalling domains. scFv, BW431/26 single chain antibody fragment; IgG1‐Fc, IgG1 CH2CH3; TM, transmembrane region; CD3ζ, CD3ζ intracellular chain; CD28, CD28 intracellular chain. (B) Peripheral blood lymphocytes from colorectal patient No 3 (a) were retrovirally transduced to express the BW431/26‐scFv‐Fc‐ζ (b) and the BW431/26‐scFv‐Fc‐CD28‐ζ. receptor (c), respectively. FACS analysis using the anti‐CD3 antibody OKT3 and the anti‐human Ig‐Fc antibody that detects the extracellular IgG1 CH2CH3 spacer domain of the receptors demonstrates expression of the recombinant receptors on the surface of CD3⁺ T cells.