Another possible explanation of the association between the upregulated IFN-I response and increased eosinophilic sinonasal inflammation is, although it was not proven in our study, IFN-I-induced overproduction of B cell-activating factor of the tumor necrosis factor family, leading to the local induction of IgA and activation of eosinophils in the NP (43–45). The gene discussed is TNFSF13B; the disease is inflammation.