Melatonin significantly counteracted the stimulatory effect of doxorubicin on the expression of some genes: MUC1, (a p53 repressor) overexpressed in cancer [29], SNAI2, involved in invasion and epithelial to mesenchymal transition [30] and BIRC5, an inhibitor of apoptosis highly expressed in doxorubicin-resistant cells [31]. The gene discussed is SNAI2; the disease is cancer.