IFNA1 and viral infectious disease: Thus, to fit in the multipolar model of macrophage polarization (Figure 1), constitutive subthreshold IFN-α/β signaling may be more hierarchical than adaptive IFN-γ and other inducible cytokines (including type I and type III IFNs produced later during viral infections) in M1 (or antimicrobial) polarization [6].