MSMB and prostate cancer: We then investigated the association of rs10993994 with circulating concentrations of MSP in EPIC and used this genetic variant as an instrument for MSP to assess its potential causal role through Mendelian randomization (MR) analyses by combining EPIC-derived estimates with published data from the Prostate Cancer Association Group to Investigate Cancer Associated Alterations in the Genome (PRACTICAL) consortium [5].