HTT and Huntington disease: G-quadruplex-forming molecules that can regulate biological processes through direct binding to specific proteins are emerging as promising therapeutic agents.28, 29, 30 Indeed, all four aptamers tested decreased mutant huntingtin’s enhancement of PRC2 activity in our cell-free PRC2 assay, and transfection of MS3 aptamer resulted in the reduced histone H3K27me3 mark only in HD NPCs expressing mutant huntingtin, measured by our bead-based PRC2 cellular assay.