SNCA and Parkinson disease: To ascertain whether the levels of contaminating endotoxin were sufficient to confound cytokine measurements in the α-synuclein cultures, we used six endotoxin standard dilutions (0, 0.1, 0.26, 0.64, 1.6, and LPS>10EU/mL) to stimulate PBMCs using otherwise identical conditions (PD n = 5, Control n = 4, age = 68.9 (not different from previous cohort) and compared supernatant cytokine concentrations with data obtained in our initial experiments (Figure 2).