(A) design of experiment to induce DYRK1A; (B) DYRK1A transcript levels following CRISPR activation in control cells or in presence of ID-8, or compounds 28, 30, or 45. Error bars, SD; **p<0.05. (C) PAX6 transcripts following DYRK1A activation in control cells or cells treated with inhibitors at 50 or 100 nM. Error bars, SD; **p<0.05; all compounds produced significant reductions at all doses at p<0.05. (D) inducible shRNA knockdown of DYRK1A in WA09 hPSC. (E) effect of DYRK1A knockdown on PAX6 transcript levels following dual SMAD induction of neural specification. Result of triplicate experiments shown, mean ±SEM, **p<0.01, ***p<0.001. Studies in A and B were carried out with derivatives of hESC line WA09, those in C and D utilised derivatives of Genea022.