Since the induction of IFNs is also subject to cell-to-cell variation (13, 15, 45), we first evaluated the expression frequency of type I IFN (e.g., beta IFN [IFN-β]) and type III IFN (i.e., IFN-λ) to determine the extent of the variation during infection. The gene discussed is IFNB1; the disease is infection.