CD28 and neoplasm: For an efficient T cell activation of TCR CARs and TCR like CARs soluble TCRs and recombinant TCR-like antibody fragments are fused to a hinge or spacer peptide and a transmembrane domain followed by the intracellular T cell signaling domains, CD3ζ or CD3ε of the T cell receptor, and costimulatory domains such as CD28 or/ and 4-1BB leading to destruction of the tumor cells (Figure 1) (Figure 2).