The serum concentration of IL-2 and IFN-γ were significantly higher in RA and OA patients than in healthy subjects (in the case of IL-2 p = 0.0001 and p < 0.0001, respectively and both p = 0.007 in the case of IFN-γ; Figure 7). The gene discussed is IFNG; the disease is rheumatoid arthritis.