At least one peptide comprising a portion of an immunogenic region of a chimeric antigen receptor and cells expressing the CAR for use in a method of treating a disease in a human subject, wherein the CAR comprises: a) an extracellular antigen-recognition domain that specifically binds to a target antigen associated with the disease in the human subject, b) an intracellular signaling domain comprising an activating cytoplasmic signaling domain and further comprising an intracellular costimulatory signaling domain of a T cell costimulatory molecule, wherein the costimulatory signaling domain is a human 4-1BB signaling domain, and c) a transmembrane domain linking the extracellular domain and the intracellular signaling domain, wherein the transmembrane domain is a human CD28 transmembrane domain, such that a junction region is formed by the joining of the human transmembrane portion of CD28 and the human 4-1BB signaling domain, wherein the junction region comprises SEQ ID NO: 137, wherein the CAR specifically binds to an antigen associated with the disease in the human subject, wherein the method comprises administering the cells expressing the CAR for treating the disease and administering the at least one peptide for inducing tolerance to the CAR, wherein the immunogenic region comprises SEQ ID NO: 137, and wherein the peptide is between 10 and 30 amino acids, and the peptide comprises the sequence of amino acids set forth in any of SEQ ID NOs 7-12, 16-22, 163, or 165, and wherein said method comprises administering the peptide prior to administration of the CAR, and said method comprises administering to the subject the at least one peptide under conditions that induce tolerance in the subject to the CAR and administering to the subject the cells expressing the CAR. wherein the CAR comprises: a) an extracellular antigen-recognition domain that specifically binds to a target antigen associated with the disease in the human subject, b) an intracellular signaling domain comprising an activating cytoplasmic signaling domain and further comprising an intracellular costimulatory signaling domain of a T cell costimulatory molecule, wherein the costimulatory signaling domain is a human 4-1BB signaling domain, and c) a transmembrane domain linking the extracellular domain and the intracellular signaling domain, wherein the transmembrane domain is a human CD28 transmembrane domain, a) an extracellular antigen-recognition domain that specifically binds to a target antigen associated with the disease in the human subject, b) an intracellular signaling domain comprising an activating cytoplasmic signaling domain and further comprising an intracellular costimulatory signaling domain of a T cell costimulatory molecule, wherein the costimulatory signaling domain is a human 4-1BB signaling domain, and c) a transmembrane domain linking the extracellular domain and the intracellular signaling domain, wherein the transmembrane domain is a human CD28 transmembrane domain, such that a junction region is formed by the joining of the human transmembrane portion of CD28 and the human 4-1BB signaling domain, wherein the junction region comprises SEQ ID NO: 137, wherein the CAR specifically binds to an antigen associated with the disease in the human subject, wherein the method comprises administering the cells expressing the CAR for treating the disease and administering the at least one peptide for inducing tolerance to the CAR, wherein the immunogenic region comprises SEQ ID NO: 137, and wherein the peptide is between 10 and 30 amino acids, and the peptide comprises the sequence of amino acids set forth in any of SEQ ID NOs 7-12, 16-22, 163, or 165, and wherein said method comprises administering the peptide prior to administration of the CAR, and said method comprises administering to the subject the at least one peptide under conditions that induce tolerance in the subject to the CAR and administering to the subject the cells expressing the CAR.