Previously, we tested deletions of nearly all non-essential yeast genes (,80% of the yeast genome) and identified 99 genes, that when deleted, altered BMV replication, revealing the involvement of many novel host pathways in viral replication, transcription, and translation [9] . However, classical yeast genetics and other approaches have demonstrated that genes essential for cell growth also make major contributions to BMV RNA replication [23, 24, 25, 26] . To more globally identify additional essential host factors critical for BMV RNA replication, we assayed a doxycycline (dox)repressible library of ,900 yeast strains, each of which allows repressing the expression of a selected essential gene by adding dox to growth media [27] . Using this genome-wide approach, we identified 24 essential host factors whose repressed expression reproducibly altered BMV RNA replication. These host factors are involved in protein homeostasis, protein trafficking, and translation, among others. The results presented here, in conjunction with previously identified host factors [2, 8, 10, 24, 25] , provide a more complete understanding of cellular pathways utilized by BMV. Dissecting the role of these essential host genes in virus replication should significantly advance our understanding of basic virus biology and virus-host interactions. Additionally, these results may lay a foundation for extending such studies to other virus groups, thus potentially identifying common cellular pathways that could be targeted for the development of broad-spectrum antivirals.