A chimeric antigen receptor (CAR) mainly consists of a single chain variable fragment (scFv) from a mAb, an extracellular hinge and spacer element, a transmembrane region (TM) and an internal signaling domain such as CD3? or Fc receptor ? cytoplasmic signaling domains (Fc?RI?). The main advantage of CAR modified T cell is that it decreases MHC restriction, which allows the adoptive immune cells to be directly activated in various types of cancers.