We found a reduction in ETNPPL mRNA levels in all six PD cases compared with the mRNA mixture of the six controls (Figure 3), which go hand in hand with the IHC outcomes obtained here, with a lack of signal in PD subjects compared with controls for ETNPPL protein at the level of SNc dopaminergic neurons but, also, with the results obtained in previous RNA sequencing data [20]. This evidence concerns the gene ETNPPL and Parkinson disease.