HSPA1A and Parkinson disease: Positive correlations were found between the HSPA1A/B and HSPA6 gene expression and also between the HSPA1A and HSPA6 gene expression levels in PBMC from both PD patients (r = 0.61, p = 0.013; r = 0.59, p = 0.0078, respectively) and HDs (r = 0.55, p = 0.017; r = 0.69, p = 0.002, respectively) (Supplementary Figure S3).