Indeed, in the Fragile X syndrome (FXS), observations suggesting increased metabotropic glutamate receptor (mGluR5) expression led to preclinical studies showing that the inhibition of mGluR5 can ameliorate multiple mutant phenotypes in mouse and drosophila models of FXS, and clinical trials based on this therapeutic strategy are underway [33]. The gene discussed is GRM5; the disease is fragile X syndrome.