NGI-1 (790702-57-7) is a cell-permeable inhibitor of oligosaccharyltransferase (OST) – IC50 = 1.1 μM.1 It blocks cell-surface localization and signaling of the epidermal growth factor receptor (EGFR) glycoprotein and selectively arrests proliferation only in cells dependent on EGFR for survival. NGI-1 caused G1 arrest and senescence in RTK-dependent NSCLC cells (PC9, HCC827, H3255,H1581). NGI-1 displays antiviral behavior against various flaviviruses (Dengue, West Nile, Yellow fever and Zika).2 It also was able to overcome resistance to EGFR tyrosine kinase inhibitors in mutant NSCLC cells3 and enhance radiosensitivity and cytotoxic effects of chemotherapy in glioma cells with high levels of RTK activation4.