A specific inhibitor of N-linked glycoslylation that blocks the first step of glycoprotein synthesis and induces protein unfolding; impairs the function of several receptor tyrosine kinases, including EGFR, ErbB2, ErbB3, IGF-IR, and ALK; radiosensitizes glioma and pancreatic adenocarcinoma cells to chemotherapy (500 nM) and disrupts cell viability in various neuroblastoma cell lines (IC50s 20 - 500 nM)