The top hits included plasma cell activation markers previously associated with MM, such as sBCMA (TNFRSF17), SLAMF7, TACI (TNFRSF13B) and BAFF (TNFSF13B, inverse association).32–36 We also observed associations for several proteins that have only very recently been linked to MM development, namely contactin-5 (CNTN5), IL5RA and QPCT (Fig. 2A and 2D).29,30 Pathway analysis revealed an enrichment of proteins associated with antibody production and plasma cell activation, JAK-STAT signaling and cytokine signaling in the years prior to MM diagnosis (Supplementary Fig. 7B). Here, IL5RA is linked to Miyoshi myopathy.