BLK and rheumatoid arthritis: All of these have previously been nominated as candidate causal genes through association of expression of disease-associated SNPs: BLK in RA through expression in B cells (21), as here, FAM119B as a candidate causal gene in MS through expression in whole blood (22), matching the colocalisation we observe across B cells and monocytes, and FAM164A through expression in lymphoblastoid cell lines (23).