The Tomm40 mRNA level significantly decreased with age in the AD mouse brain and was significantly lower in the AD mouse brain than in the control mouse brain at 52 w.o.a. The Pink1 mRNA level was significantly higher in the AD mouse blood than in the control mouse blood at both 12 and 52 w.o.a. The Pink1 mRNA level tended to increase with age and was usually lower in the AD mouse brain. The gene discussed is PINK1; the disease is Alzheimer disease.