HCFC1 and infection: Baculovirus Autographa californica multiple nucleopolyhedrovirus (AcMNPV) replicates in both Spodoptera frugiperda Sf21 and Trichoplusia ni Tn368 cells, whereas AcMNPV defective in hcf-1 (host cell-factor 1) gene productively infects only Sf21 cells, indicating that HCF-1 is indispensable for the AcMNPV productive infection of Tn368 cells.