Notably, the association of GDF15 with IL-6 was nearly twice as strong among APOEε3 homozygotes (r = 0.29; P < 0.0001) as it was among APOEε4 carriers (r = 0.16; P < 0.0001; Fig. 5B-C; Supplementary Table 18), suggesting that genetic predisposition for AD may influence the responsiveness of GDF15 – a stress response protein with known immunosuppressive function – to IL6-mediated inflammation. Here, IL6 is linked to Alzheimer disease.