RPS6KB1 and fragile X syndrome: Considering that the ERK1/2–S6K1 and PI3K–S6K1 signalling cascades commonly mediate multiple Gq-coupled receptors and ADCY1 positively regulates both ERK1/2 and PI3K in FXS, inhibition of ADCY1 may offer a potential strategy to normalize the hyperactivity of multiple pathological factors (Fig. 7).