GRN and Alzheimer disease: Zhan et al. connected AD risk alleles to downstream proteins using AD GWASs, cis-eQTLs, and cis-pQTLs and used two-sample Mendelian randomization with extensive sensitivity analyses to nominate five plasma proteins—BLNK, CD2AP, GRN, PILRA and PILRB—as putatively causal, with GRN (protective) and BLNK among the strongest candidates [21].