Figure 1.

Generations of chimeric antigen receptors (CARs). CARs typically have an extracellular antigen recognition domain represented by an antibody-derived single-chain variable fragment (scFv) which contains a variable heavy (VH) chain and a variable light (VL) chain connected by a linker, a hinge, a transmembrane domain, with or without one or two costimulatory domains, and a CD3ζ. The fourth-generation CARs additionally have a “nuclear factor of activated T cell-responsive expression” element for an inducible transgenic product.