ABCG1 and rheumatoid arthritis: Also, methotrexate seems to exert other cardioprotective properties on lipids and endothelium in RA patients, as serum of patients treated with methotrexate showed an increased cholesterol efflux capacity mediated by ABCG‐1 and scavenger receptor class B type I. In vitro, methotrexate inhibits foam cell formation by promoting reverse cholesterol transport through activation of adenosine A2 receptor, and it increases in cholesterol 27‐hydroxylase and ABCA‐1.35, 36