Among these, negative causal associations with RA were observed for 10 proteins (APOBR, CFB, DDR1, DXO, EVI5, FCGR2A, HLA-E, IFNGR2, IL6R, and TNXB), while positive causal associations were observed for 12 proteins (CD40, CDSN, FCRL1, FCRL3, HLA-DRA, HSPA1A, ICAM3, KLRD1, SWAP70, TFF1, TGOLN2, and WFIKKN2). Here, CD40 is linked to rheumatoid arthritis.