Small molecule‐specific CAR T cell killing (A) Schematic representation of the small molecule specific‐CAR T cells against fluorescein (FL) (Upper) and MPOB (Lower). (B) Diagram showing the construction of anti‐small molecule CAR, where SP; signal peptide, scFv; single chain variable fragment that recognizes small molecules, Hinge; hinge domain from CD8, CD28; transmembrane and costimulatory domains from CD28, 4‐1BB; costimulatory domain from CD137, CD3ζ; activation domain from CD3ζ; 2 A: 2 A peptide, CD19 t (truncated CD19); extracellular and transmembrane domains from CD19 (C) MDA‐MB‐468 cells were labeled with α‐EGFR‐FL or α‐EGFR‐MPOB, and antigen‐specific cytotoxicity was tested after co‐incubation of labeled MDA‐MB‐468 cells with non‐transduced (NTD), FL‐CAR and MPOB‐CAR T cells. (n=3). P values were determined by unpaired Student's t test. ****P<0.0001.