More recently, Vershkov et al. used FXS iPSCs to test a library of 140 compounds for their ability to rescue the expression of FMR1. A combination of the DNA methyltransferase inhibitor 5-azadC and the SAH hydrolase and histone methylation inhibitor DZNep was most effective in iPSCs, whereas a sustained increase in FMR1 expression in FXS iPSC-derived NPCs was even observed after treatment with 5-azadC alone. The gene discussed is FMR1; the disease is fragile X syndrome.