For example, the probability of dementia in APOE ε3ε4/ε4ε4 carriers with a PBV 0.3 units higher was equal to that of APOE ε3ε3 carriers, and with a PBV 0.6 units higher it was equal to that of APOE ε2ε3 carriers. This evidence concerns the gene APOE and dementia.