Here, using single-molecule detection techniques for soluble aggregates (Fig. 1, Supplemental Fig. 3), we first characterised the organoid conditioned media of single T21 and D21 iPSC clones from an isogenic DS model [52] (see also Supplemental Fig. 1) which did not show Aβ plaque and tau tangle histopathologies [43] (see also Supplemental Fig. 2). This evidence concerns the gene MAPT and Dravet syndrome.