Three SNPs (res12907866, rs17601241, and rs4646) in CYP19 were assessed in 319 AD patients and 110 controls representing men and women, and the investigators determined that while none of these CYP19 SNPs increased the risk for AD, women with the rs4636 genotype carrying a T allele were more likely to have an earlier-onset of AD (Corbo et al., 2009). Here, CYP19A1 is linked to Alzheimer disease.