Both patients present normal responses to other viruses in PBMCs and fibroblasts. (a) PBMCs from a control (C+), P1, P2, and P2’s parents were challenged with several viruses with different types of genomes: dsDNA viruses (HSV-1, UV-inactivated HSV-1 or HSV-1i, and BK), negative-strand ssRNA viruses (VSV, NDV, measles, Sendai virus, human parainfluenza virus III [Para-III], and mumps), and positive-strand ssRNA viruses (Sindbis virus and EMCV). Levels of IFN-α were assessed by ELISA 24 h after infection. P2 and her parents’ cells were not tested for their response to infection with Sindbis and measles. This experiment was performed once. (b) Production of IFN-β and IFN-λ, as assessed by ELISA, in control (C+), P1, P2, UNC-93B^−/−, and NEMO^−/− fibroblasts 24 h after infection with positive-strand ssRNA viruses (Sindbis virus at an MOI of 10 and EMCV at an MOI of 1) and negative ssRNA viruses (measles at an MOI of 1 and parainfluenza virus III at an MOI of 1). Values represent mean values ± SD from three independent experiments. NS, nonstimulated.