MKI67 and neoplasm: These results confirm and extend previous evidences of effective ATM inhibition by the employed doses of KU60019 as determined by TP53-phosphorylation assays, radiosensitization of the same GIC lines used for orthotopic tumor development and the induction of the proliferative marker KI67 in vivo, consequent to release of the G1/S, intra-S and G2/M checkpoints10,12,13.