We gratefully thank J. Jiang, N. Sinnott-Armstrong, B.W. Kunkle, A. Nicolas, M.A. Nalls et al., and all investigators and related consortia for conducting studies of growth differentiation factor 15 (pmid, 29628937 and 33462484), Alzheimer’s disease (30820047), Parkinson’s disease (31701892), and amyotrophic lateral sclerosis (29566793) and sharing GWAS summary statistics. The gene discussed is GDF15; the disease is Parkinson disease.