Abstract: Provided herein are methods of treating a human patient, comprising administering to the human patient an inhibitory immune checkpoint inhibitor or stimulatory immune checkpoint activator and administering to the human patient a population of human cells comprising antigen-specific T cells that are derived from a T cell line restricted by a subdominant HLA allele or HLA allele combination. Also provided are methods of selecting such a T cell line and methods of selecting a T cell donor from whom to derive such a T cell line, for therapeutic administration to a human patient in combination with administration of an inhibitory immune checkpoint inhibitor or stimulatory immune checkpoint activator. Also provided are pharmaceutical compositions comprising an inhibitory immune checkpoint inhibitor or stimulatory immune checkpoint activator and a population of human cells comprising antigen-specific T cells that are derived from a T cell line restricted by a subdominant HLA allele or HLA allele combination.