H2AX and non-small cell lung carcinoma: In contrast, the accumulation of γ-H2AX and recruitment of 53BP1 were reduced in cells treated with the APE1-redox inhibitor APX3330 or with the previously reported APE1 endonuclease inhibitor CRT0044876, which demonstrated no cytotoxic effects in NSCLC cells, even at high concentrations.