NPC1 and infection: While WT and the two non-cleavage mutant viruses, NP-DEVA and NS1-DEVA, produced only full-length NP and NS1 proteins, those proteins of cleavage mutant viruses, NP-C, NS1-C, and DM-C, were efficiently cleaved from 9 hours post-infection (hpi) (Fig. 1D).