Inhibitory chimeric antigen receptors

A method for treating a patient in need thereof comprising:

• (a) providing an immune cell;
• and (b) administering said immune cell to said patient, wherein the immune cell comprises:
• a first CAR comprising an extracellular domain comprising an antigen binding domain, a transmembrane domain, and an intracellular domain;
• and
• a second CAR comprising an extracellular domain comprising an antigen binding domain, a transmembrane domain, and an intracellular domain, wherein:
• the intracellular domain of the second CAR comprises an Immunoreceptor Tyrosine-based Switch Motif (ITSM), wherein said ITSM is a sequence of amino acids TX1YX2X3X4 (SEQ ID NO:
• 2049), wherein
• X1 is E;
• X2 is A or S;
• X3 is S or E;
• and
• X4 is V or I;
• and
• the intracellular domain of the second CAR has at least 95% amino acid sequence identity with SEQ ID NO:
• 2016.