Indeed, both A2AR and mGlu5R antagonists have been demonstrated to be effective in animal models of Alzheimer’s disease [11,34,35,36] and of fragile X syndrome [37,38,39,40], in which increases in the expression and activity of STEP have been demonstrated [12,37,41,42]. This evidence concerns the gene ADORA2A and early-onset autosomal dominant Alzheimer disease.