This document provides isolated immune cells that include an exogenous T cell receptor (TCR) having affinity for an Ataxia-Telangiesctasia Mutated (ATM) peptide, an exogenous TCR having affinity for an AT-rich interactive domain-containing protein 1A (ARID1A) peptide, or both an exogenous TCR having affinity for an ATM peptide and an exogenous TCR having affinity for an ARID1A peptide, as well as methods and materials for making such immune cells. For example, isolated immune cells that included an exogenous TCR having affinity for a mutant ATM and/or exogenous TCR having affinity for an ARID1A peptide, methods and materials for making such immune cells, and methods and materials for using such immune cells to treat mammals (e.g., a human having cancer) are provided.