The ATR protein plays a crucial role in the DNAdamage response, particularly in cancer cells where the G1 checkpoint is oftenlost due to mutated tumour suppressor genes.62 Elimusertib andberzosertib are examples of ATR inhibitors currently under investigation inphase I or early phase II clinical trials in participants with NECs (NCT04514497and NCT04802174, Table3). Here, ATR is linked to neoplasm.