PSEN1 and Alzheimer disease: In their study, only four SNPs in the NGFR gene were selected, and rs2072446 was also shown to be associated with an increased risk of “familial AD” (defined as those with at least two first‐degree relatives in two generations with AD, and no mutations in APP, PSEN1, and PSEN2 genes) in the codominant genetic model (C/T vs. C/T, OR = 3.01, 95% CI = 1.00–9.12, p = 0.016).