ChIP and ChIPseq were performed as described previously (20 (link), 21 (link)). Antibodies used were anti-ASCL1 (Abcam) and anti-IgG (Abcam). ChiPSeq data and full associated methods are both available as an associated file at the GEO database https://www.ncbi.nlm.nih.gov/geo/ and assigned the identifier GSE153823. ChIPseq experiments were performed in two separate clones of each of WT and S-A SH-SY5Y tetracycline-inducible stable cell lines induced with 1 μg/ml doxycycline for 24 hours in four biological replicates. Differential binding analysis (Diffbind) was performed as described previously (20 (link)). ChIP-qPCR primer sequences are provided in Supplementary Table S1.