GRP and type 2 diabetes mellitus: We 1) identify 256 unreported protein quantitative trait loci (pQTL), 2) demonstrate shared genetic regulation of 224 cis-pQTLs with 575 specific health outcomes, revealing examples for important metabolic diseases, like gastrin releasing peptide as a potential therapeutic target for type 2 diabetes, 3) improve causal gene assignment at 40% (n=192) of overlapping risk loci, and 4) observe convergence of phenotypic consequences of cis- pQTLs and rare loss-of-function gene burden for twelve proteins, like TIMD4 for lipoprotein metabolism.