KIN1408 is a small molecule that targets factors at or above the level of MAVS in the RLR signaling pathway to drive IRF3 activation (IRF3 nuclear translocation ECmax = 5 µM in 20 h; Huh7 cells) without significant cytotoxicity (50 µM/20 h in Huh7 or 20 µM/36 h in HEK293 cultures). KIN1408 induces cellular transcription of innate immune genes (Eff. conc. 1.25-20 µM in 20 h; PMA-differentiated THP-1 cells) in a MAVS- and IRF3-dependent manner and exhibits broad-spectrum anti-viral activity (Eff. conc. 1-5 µM), including dengue virus 2 (DV2; Huh7), influenza A (IAV H3N2; HEK293), RSV (A2 strain; HeLa), Ebola (EBOV strain Zaire; HUVECs), Nipah virus (NiV; HUVECs), and Lassa virus (LASV; HUVECs). MAVS signaling activation upon Zika virus infection or KIN1408 treatment is reported to result in pTBK1 mitochondria relocalization and caspase 3-mediated apoptosis in human neuroepithelial stem (NES) cells.