ISG15 and infection: LV-shDUSP1 infection enhanced mRNA expression of myxovirus resistance protein A (MxA), 2'-5'-oligoadenylate synthetase 1 (OAS1), ISG15 ubiquitin-like modifier (ISG15), chemokine C-X-C motif ligand 10 (CXCL10), and USP18 relative to those in LV-cont-infected cells (P < 0.05; Fig. 4).