ATR and neoplasm: To this end, Chou-Talalay method using CalcuSyn software [31, 32], which has been widely accepted to study synergistic drug interactions [33–36], was used to determine the best anti-tumor effect using CDDP (12.3 μM) and different concentrations of ATR inhibitor Bezosertib in DDUP high-expressed PDOVC#3 and PDOVC#4.