An increase in caspase 3/7 positivity was observed in both melanoma cell lines for direct NTP treatment (69.2 ± 11.1% for A375, p ≤ 0.0001 and 72.3 ± 12.0% for SK-MEL-28, p ≤ 0.0001) and indirect NTP treatment (38.3 ± 1.4% for A375, p ≤ 0.0001 and 31.5 ± 8.2% for SK-MEL-28, p ≤ 0.0001) (Fig. 3a), further evidencing that the apoptotic pathway was activated. This evidence concerns the gene CASP3 and melanoma.