SAA2 and Parkinson disease: The qRT-PCR analysis from 33 PD patients and 37 controls demonstrated a significant 1.68-fold downregulation of Saa2 gene (p = 0.0372) and 1.34-fold downregulation of Saa1 gene in PD patients skin, however the result was not statistically significant (p = 0.2469) (Figure 1).