The study by Kadowaki et al. investigates the role of natural interferon α/β–producing cells (IPCs) in linking innate and adaptive immunity. Viral stimulation not only triggers IPCs to produce large amounts of antiviral interferons but also induces these cells to differentiate into dendritic cells (DCs). The produced interferons and tumor necrosis factor α (TNF-α) act as autocrine survival and differentiation factors, respectively. Virus-induced DCs stimulate naive CD4+ T cells to produce interferon-γ and interleukin (IL)-10, contrasting with IL-3-induced DCs, which promote Th2 cytokine production. This suggests that IPCs play dual roles in antiviral immune responses: directly inhibiting viral replication and triggering adaptive T cell-mediated immunity by differentiating into DCs. The findings highlight the critical role of IPCs in integrating innate and adaptive immune responses and their potential as therapeutic targets for various diseases.The study by Kadowaki et al. investigates the role of natural interferon α/β–producing cells (IPCs) in linking innate and adaptive immunity. Viral stimulation not only triggers IPCs to produce large amounts of antiviral interferons but also induces these cells to differentiate into dendritic cells (DCs). The produced interferons and tumor necrosis factor α (TNF-α) act as autocrine survival and differentiation factors, respectively. Virus-induced DCs stimulate naive CD4+ T cells to produce interferon-γ and interleukin (IL)-10, contrasting with IL-3-induced DCs, which promote Th2 cytokine production. This suggests that IPCs play dual roles in antiviral immune responses: directly inhibiting viral replication and triggering adaptive T cell-mediated immunity by differentiating into DCs. The findings highlight the critical role of IPCs in integrating innate and adaptive immune responses and their potential as therapeutic targets for various diseases.