Phosphorylation of RAB12 is prominent in the brain in PD models and observed to be higher than other RAB substrates, such as RAB10, in this organ.49,50 Functionally, other studies showed that RAB12 is located in phagosomes, lysosomes and late endosomes, where it might regulate endosome-to-trans-Golgi trafficking and exocytosis.73,74 Ours is the first report of hyperphosphorylated RAB12 in PBMCs from a large clinical cohort of G2019S carriers. This evidence concerns the gene RAB12 and Parkinson disease.