We are thrilled to learn that the FDA-approved trofinetide (DAYBUETM), an oral small molecule synthetic analog of glycine-proline-glutamate (GPE), an N-terminal tripeptide derivative of IGF-1, as the first drug for the treatment of RTT in adult and pediatric patients two years of age and older in March 2023 [46]. This evidence concerns the gene IGF1 and Rett syndrome.