We tested several obvious candidates that might be important during viral infection, such as the type I IFN receptor, or the costimulatory receptors 4-1BB [12] and GITR [13] but did not find any defects in the CD8 T cells from uninfected NOD2−/− as compared to WT mice before or after activation in vitro. Here, TNFRSF18 is linked to viral infectious disease.