Silencing Ryk did not alter co‐regulator motif profiles in either HD or C116 cells, except for Tbrain factor motifs as detected in HD cells with Ryk silencing (Figure S3), supporting a model in which Ryk signaling modulates FOXO3 gene regulation by altering the stoichiometry of the FOXO3/ß‐catenin/Ryk‐ICD complex (Figures 1 and 2). This evidence concerns the gene RYK and Huntington disease.