A molecular mechanism of carnosol on CIA arthritis appears to be via an inhibiting effect on Th17 cell differentiation by diminishing STAT3 phosphorylation and favoring Treg cell immunosuppressive function through inhibition of IL-6-IL-6R (CD126) signaling, indicating that administration of carnosol can be applied as a potential therapy for patients with RA. The gene discussed is STAT3; the disease is rheumatoid arthritis.