Figure 1.
Overview of CAR designs from first to fourth generation. Blue: single-chain variable fragment (scFv) consisting of the heavy and light chain of the binding domain of antigen-specific antibodies coupled by a linker peptide; grey: transmembrane domain; yellow: co-stimulatory domain of CD28; orange: co-stimulatory domain of 4-1BB (CD137); green: activating domain consisting of the CD3ζ domain of the T-cell receptor; pink: nuclear factor of activated T-cells (NFAT); purple: interleukin-12 (IL-12) which is expressed after binding of NFAT to an NFAT-driven IL-12 cassette.