A nucleic acid molecule comprising a nucleotide sequence encoding an inhibitory chimeric antigen receptor (i CAR) capable of preventing or attenuating undesired activation of an effector immune cell, wherein the i CAR comprises an extracellular domain that specifically binds to a single allelic variant of a polymorphic cell surface epitope absent from mammalian tumor cells due to loss of heterozygosity (LOH) but present at least on all cells of related mammalian normal tissue； and an intracellular domain comprising at least one signal transduction element that inhibits an effector immune cell is provided. Vectors and transduced effector immune cells comprising the nucleic acid molecule and methods for treatment of cancer comprising administering the transduced effector immune cells are further provided.
