RPS6KA1 and early-onset autosomal dominant Alzheimer disease: Moreover, our study, for the first time, identify RSK1 as an upstream regulator of AKT-GSK3β signaling cascade, enhancing AKT signaling while simultaneously inhibiting GSK3β activity, thereby underscoring the critical role of RSK1 in Tau phosphorylation and associated illnesses, such as HAND and Alzheimer's disease.