SLC1A2 and Parkinson disease: The total EAAT2 expression showed a modest but non-significant decrease in the iPD group (Supplementary Fig. 1e, online resource—LRRK2 G2019S PD cases vs age-matched controls; p = 0.001; LRRK2 G2019S PD cases vs iPD cases; p = 0.07; age-matched controls vs iPD cases; p > 0.99).