The CD3<sup>+</sup>CD4<sup>-</sup>CD8<sup>-</sup> double-negative (DN) T cell population in tumor samples also emerged as a contributing factor in this context.<h4>Conclusions</h4>These results demonstrate that ATR blockade concurrently enhances the efficacy of genotoxic agents and immune checkpoint inhibitors, thus paving the way for combination therapies in NSCLC. Here, CD4 is linked to non-small cell lung carcinoma.