To study the effect of these inhibitors on FMR1 expression in disease-relevant neural cells, we generated induced pluripotent stem cells (iPSCs) from three different FXS fibroblast cell lines and then differentiated these into neural stem cells (NSCs) and neurons as described in the Materials and Methods section (Figure S1 for 13-1, Figure S2 for 15C). Here, FMR1 is linked to fragile X syndrome.