IL18 and rheumatoid arthritis: The present cross-sectional study aimed to analyse the expression of pro-inflammatory cytokine genes TNFA, IL6, IL12B, IL23, IL18 and immunoregulatory genes FOXP3, TGFB1, and IL10 in PBMCs of patients with rheumatoid arthritis at mRNA levels in relation with disease characteristics, as well as to identify some potential biomarkers for disease activity in RA.