Notably, we have previously shown that having APOE risk variants were associated with a higher prevalence of anti-HSV IgM antibodies in the NSHDS sample6, thus an association that seems to be negatively modified by PILRA. Figure 1C illustrates that PILRA R78G A/A homozygosity also could have a protective impact on the HSV-1 associated AD risk, although not statistically significant (Table 3). Here, APOE is linked to Alzheimer disease.