Although one study found greater PiB-PET increases in patients with higher WMH[30] and another found a relationship between higher WMH and higher PiB-PET retention in apolipoprotein E ε4 carriers only,[31] our study findings are similar to the largest study in cognitively normal elderly which found that WMH and PiB-PET were not correlated.[32] Except in the specific context of cerebral amyloid angiopathy,[33] it seems likely that beta-amyloid deposition and WMH accrue as part of independent processes. The gene discussed is APOE; the disease is cerebral amyloid angiopathy.