SKMEL28 cells were treated with different compounds at various concentrations. Late apoptotic marker, IncuCyte® Cytotox Green was imaged and measured using IncuCyte S3 live-cell analysis system. The histogram represents data collected at 30 h post-treatment. Experiments were performed in triplicates and error bars indicate SD. ****, P < 0.0001; ***, P = 0.0002; **, P < 0.002; *, P = 0.02; n.s., not significant.