Furthermore, tau phosphorylation is known to increase in the cerebrospinal fluid (CSF) in patients with Alzheimer’s disease (65), and the rs1006737 variant of CACNA1C is significantly associated with hyperphosphorylated tau/total tau ratio in the CSF of patients with bipolar disorder (66). The gene discussed is CACNA1C; the disease is early-onset autosomal dominant Alzheimer disease.