SH-SY5Y cells were differentiated by using 10 μM retinoic acid for 6 days and subsequently exposed to melatonin (0.1, 1, 10, and 100 μM/mL) for 24 h. MPP+ (400 μM) was used to induce the PD model. For gene silencing, cells were transfected with HSF1-specific siRNA or control siRNAs for 24 h, then the cells were incubated with melatonin and MPP+ for 24 h. This evidence concerns the gene HSF1 and Parkinson disease.