In conjunction with human data of loss-of-function alleles of CETP that protect against dementia in APOE-ε4 + carriers and preclinical data in a humanized rodent model of dementia that show rescue of cognition loss by a CETP-inhibition, these results suggest that CETP-inhibition might be repurposed for treatment of dementia in APOE-ε4 + carriers. The gene discussed is CETP; the disease is dementia.