The greasy response to virus infections.

Virus replication requires lipid metabolism, but how lipids mediate virus infection remains obscure. In this issue, Amini-Bavil-Olyaee et al. (2013) reveal that IFITM proteins disturb cholesterol homeostasis to block virus entry. Previously, in Cell, Morita and colleagues (2013) showed the antiviral potency of the lipid mediator protectin D1.