In RA, ACE/ACE2 ratio did not change after 6 M (4.87 [3.0–7.1] ng/UF; p = 0.069) but significantly increased after 12 M (4.52 [3.4–6.8] ng/UF; p = 0.035) vs. B (4.24 [2.6–6.1] ng/UF). Here, ACE2 is linked to rheumatoid arthritis.