CD4 and lupus nephritis: In accordance with our result of increased IFN-γ production in MRL-FaslprKSRP−/− mice (Figure 3b), it has been demonstrated that in MRL-Faslpr mice, IFN-γ receptor signaling is important for lupus nephritis development [30] and increased IFN-γ expression in the kidneys, mainly driven by CD4+ T cells, has been described as well [31,32].