RIGI and neoplasm: Identified mechanisms of selectivity of NDV for tumor cell oncolysis in non-permissive hosts include the following: (i) defects of tumor cells in activation of anti-viral signaling pathways (via RIG-I), (ii) defects of tumor cells in type I IFN signaling pathways (via IFNAR), (iii) defects of tumor cells in apoptotic pathways [61].