CD4 and inflammation: Moreover, blocking of Notch signaling by GSI, which has been used in clinical trials as a cancer therapy approach, abrogated the survival and pathogenesis of lung inflammation with a decreased number of IFN-γ+CD4+ and IFN-γ+CD8+ T cells, suggesting the pivotal role of Dll1 through Notch signaling in driving IFN-γ mediated immune response to influenza virus.