Apolipoprotein E (apoE) polymorphism is associated with onset of Alzheimer's disease (AD). We found seven polymorphisms in apoE receptor 2 (ApoER2), an apoEbinding receptor, in Japanese sporadic AD patients, but no association of ApoER2 polymorphisms with AD. We consider that the functions of ApoER2 in the brain may be compensated for by those of other apoE-binding receptors such as VLDL receptor.