However, there were significantly more PCNA-positive cells in PD-DBS brains (mean ± SEM; dorsal 60.4±10.71; middle 71.14±12.68) compared with normal brains (dorsal 17.5±5.80, P = 0.0252; middle 26.6±9.801; P = 0.0303). This evidence concerns the gene PCNA and Parkinson disease.