Our results show that the combination of lurbinectedin and gemcitabine induced a significant increase of γ-H2AX levels [a surrogate marker of DSBs (Mah et al., 2011)] and clear caspase-3 activation (apoptosis induction), which were recorded in two different tumor xenografts after 24 h of drug treatment. Here, CASP3 is linked to neoplasm.