Although there is no drug on the market that specifically targets macrophages to treat RA, in vitro research has revealed that CTLA4-Ig (abatacept) can lower some cytokines made by M1-like macrophages, additionally, after receiving CTLA4-Ig, macrophages transform into anti-inflammatory M2-like macrophages (38). Here, CTLA4 is linked to rheumatoid arthritis.