Treatment with Nutlin-3, a compound used for cancer clinical trial, specifically inhibits the interaction between MDM2 and its target proteins tumor protein P53 (TP53) and histone deacetylase 1 (HDAC1) and rescues both adult hippocampal neurogenic and behavioral deficits in both young adult and mature adult FXS mice. The gene discussed is HDAC1; the disease is cancer.