 Studies suggest that glycogen synthase kinase-3β (GSK-3β) and cyclin-dependent protein kinase 5 (Cdk5) are highly expressed in Alzheimer's disease and are some of the protein kinases responsible for inactivating CRMP-2 in Alzheimer's disease.This inactivation of CRMP-2 in people with Alzheimer's disease promotes the expression of neurofibrillary tangles and plaque neurites which are consistent with people suffering from this disease.CRMP-2 is also related to bipolar disorder and schizophrenia, likely as a result of the phosphorylation of CRMP-2 by GSK-3β.