IFNG and rheumatoid arthritis: Similar to the frequency analysis by flow cytometry, a significantly decreased number of α-GalCer reactive cells was found for IFN-γ as well as for IL-4 in RA patients as compared with healthy control individuals (2.3 ± 0.6 spots versus 24.3 ± 10.1 spots for IFN-γ and 0.2 ± 0.1 spots versus 3.9 ± 1.1 spots for IL-4 per 2 × 105 cells for RA patients and healthy control individuals, respectively; P < 0.05).