OLAH (oleoyl-ACP hydrolase) is a cytosolic enzyme that catalyzes the hydrolysis of oleoyl-acyl-carrier protein to release free fatty acids, particularly oleic acid and medium-chain fatty acids (C10-C16), during lipid biosynthesis 1. This enzyme plays critical roles in both viral pathogenesis and placental function. In respiratory viral infections, high OLAH expression drives life-threatening disease through enhanced lipid droplet dynamics and increased viral replication in macrophages; olah-/- mice infected with lethal influenza survived with mild disease and reduced lung inflammation 1. OLAH expression is elevated in severe COVID-19, RSV, and seasonal influenza, but not in mild infections 1. Beyond viral immunity, OLAH is highly expressed during normal lactation in mammary epithelial cells, supporting milk synthesis 2. In pregnancy, placental OLAH levels are altered in preeclampsia and fetal growth restriction; silencing OLAH in cytotrophoblasts affects apoptosis-related genes and oxidative stress markers, suggesting a role in placental dysfunction 3. These findings position OLAH as a potential therapeutic target for mitigating severe viral disease and placental disorders, though its precise regulatory mechanisms in these contexts require further investigation.