RNASEL and Parkinson disease: This is consistent with our results, where the reduction in circRNAs in PD we observed coincides with increased expression of RNASEL and EIF2AK2 (Fig. 4e, f, Supplementary Data 1), as well as the upregulation of genes related to antiviral activity and the innate immune response (Fig. 2c, Supplementary Data 2, 3).