IFNG and rheumatoid arthritis: Th1 and Th2cells have distinct roles in the development and progression of RA.57 Th1 cells and their cytokines (IFN-γ,TNF-α, IL-1β) are notable in early stages and contributeto the accumulation of dendritic cells and neutrophils in synovium.58 In addition, IFN-γ influences diseaseseverity too.59 Th1 cells create a pro-inflammatorysynovial environment via cytokines, leading to bone/cartilage degradation.60 In contrast, Th2 cells have a protective rolein the early and late stages of RA.