The present invention provides an extracellular anti-linker/label epitope chimeric antigen receptor (anti-LLE CAR) comprising I) a linker/label epitope (LLE) binding domain, II) a transmembrane domain, and III) a signal transduction domain, wherein said extracellular LLE binding domain binds a target cell binding molecule (TCBM) comprising i) an antigen binding moiety (ABM), wherein said ABM binds specifically to an antigen expressed on a target cell, ii) a label moiety (LaM), wherein said LaM is a naturally occurring molecule in a subject or a derivative thereof, iii) a linker moiety (LiM) conjugating said ABM and said LaM, thereby forming a linker/label epitope (LLE), wherein said extracellular LLE binding domain binds said LLE with a higher preference than said naturally occurring molecule.
