The present disclosure provides gene edited modified immune cells or precursors thereof (e.g., gene edited modified T cells) comprising an exogenous T cell receptor (TCR) and/or a chimeric antigen receptor (CAR) having specificity for a target antigen, and an insertion and/or deletion in one or more endogenous gene loci, wherein the endogenous gene loci encode regulators of T cell function, thereby resulting in immune cells having enhanced function. Compositions and methods of treatment are also provided. The present invention provides methods of screening for TCR- or CAR-T cells with enhanced immune function (e.g., T cell efficacy, T cell memory, and/or T cell persistence).