Nevertheless, abnormally activated CDK5 was observed in neurodegenerative diseases.43 3HB could improve neurodegenerative diseases such as Alzheimer’s disease and Parkinson’s syndrome, while the current mechanism was only limited to its anti-inflammatory and antioxidant stress effects.44–46 For future studies, the effect of 3HB on CDK5/p35 provides a new molecular mechanism for the treatment of neurodegenerative diseases. Here, CDK5 is linked to early-onset autosomal dominant Alzheimer disease.