HDAC9 and neurodegenerative disease: Thus, we can conclude that activation of AMPK/SIRTs-modulated signaling pathways, inhibition of mTOR effects (e.g., by inhibition of IIS pathway) and modulation of gene expression (e.g., by HDAC inhibitors) can alleviate aging processes (hallmarks) through direct and indirect manner (e.g., improvement of one of aging hallmarks, such as telomere attrition can improve other aging hallmarks, such as senescence and mitochondrial dysfunction), leading to extended lifespan and delay the appearance of neurodegenerative diseases.