Fig. 2.

Types of CAR-T developed. Several different strategies have been developed involving CAR-Ts owing to their flexible nature. A Bi-specific CAR, targeting two antigens independently. B iCAR, targeting two independent antigens leads to inhibition (thus sparing healthy tissues). C Intra-CAR-T can be designed to target antigens that are located intracellularly but expressed via MHC. D Syn-Notch CAR-T where a secondary-targeting antigen is strongly controlled by binding of a primary one. E Split CAR-T are created by targeting two independent antigens with the co-stimulatory domains split. Thus, only when both antigens are present is the CAR-T fully activated. F Supra-CAR: the CAR-T construct is split allowing for one co-stimulatory domain (B-zip) to bind several targeting domains (A-zip). G Tan-CAR-T are achieved by fusing two antigen-targeting domains into one. H Trivalent CAR-T, where three independent antigen-targeting CAR-T are expressed independently within the same cell. I Uni-CAR-T consist of an antigen-binding domain that bind not an endogenous target but a soluble one administered exogenously acting as a bridge (purple)