Samples were genotyped using the Affymetrix 6.0 and Illumina (610 Quad, Human660W-quad Beadchip, Omni5, OmniExpress Beadchip, Oncoarray) platforms. Each of the GWAS was subjected to rigorous standardised quality control independently prior to imputation, which was performed via the Michigan imputation server (https://imputationserver.sph.umich.edu/) based on the Haplotype Reference Consortium (HRC)29 (link). After imputation, each site was filtered to include only imputed variants with information score>0.6 and further quality controls checks were implemented (genotype rate >95%, minor allele frequencies >0.01, and Hardy-Weinberg equilibrium (HWE) >x10−5 in controls). Finally, the data were pooled and final quality control was performed on the pooled GWAS set including checks for missingness, duplicates, sex mismatch, abnormal heterozygosity, cryptic relatedness, population outliers (principal components analyses: Eigenstrat), and genomic inflation (λ > 1.00). Additional information on the MM GWAS studies contributing in the InterLymph consortium are showed in supplementary table 1.