PON1 and rheumatoid arthritis: In 2020, J. Parada-Turska, G et al. found that the PON1 concentration was reduced in the group with high disease activity compared to the group with low disease activity (Parada-Turska et al., 2020), based on the Disease Activity Score of 28 joints (DAS28) and erythrocyte sedimentation rate (ESR) (DAS28-ESR), suggesting a potential association between PON1 and the prognosis of RA.