This directory contains the variant data necessary to carry out the analyses described in the manuscript: 'The immunoproteome and multimorbidity: a Mendelian randomisation study'.Multimorbidity presents challenges for research and healthcare. We investigated how immune-proteins influence multiple diseases to identify shared mechanisms and therapeutic opportunities. Using six large plasma proteome GWAS, we identified cis-acting variants for 151 immune-proteins and applied cis-Mendelian randomisation to assess associations with 64 diseases and biomarkers. Replication was sought in independent pQTLs, with colocalisation applied to replicated signals. We found strong genetic support for druggable immune-proteins with pleiotropic effects across common diseases, highlighting opportunities for indication expansion and therapeutic development.