In this study, we performed a comparative analysis of proteostasis system components, focusing on HSP70 proteins, basal levels of the transcriptional activity of the encoding HSPA genes, and intracellular macroautophagy-associated p62 protein value in PBMC of patients with idiopathic mild to moderate PD and age-matched healthy donors. This evidence concerns the gene SQSTM1 and Parkinson disease.