Antitumoral efficacy of NDI-NIs is independent from tumor histotype, telomerase activity, and BRCA status. Human cervical (HeLa), colorectal (HT29) (A), bone (U2OS and MG63) (B), and breast (MDA-MB-231 and MDA-MB-436) (C) cancer cells were treated with the indicated compounds for 48 h and processed for cell viability assay. The histograms represent the mean values ± S.D. of three independent experiments, expressed as a percentage of cell viability over the untreated cells. *P< .05, **P< .01, ***P < .001, and ****P< .0001.