Splicing of Xbp1 was detected in 3 of 10 PD+GBA brains (N370S/wt, R463C/wt, L444P/wt) and 2 of 6 sporadic PD brains, compared to 1 of 6 control brains (Supplementary Fig 5). This evidence concerns the gene XBP1 and Parkinson disease.