LDAH (lipid droplet-associated hydrolase) is a serine hydrolase that localizes to lipid droplets and plays complex roles in cellular lipid homeostasis 12. The protein translocates from the endoplasmic reticulum to newly formed lipid droplets upon oleic acid loading and promotes microtubule-dependent lipid droplet fusion 2. LDAH exhibits opposing effects on lipid metabolism: it stimulates cellular triglyceride accumulation while promoting cellular cholesterol release 12. Mechanistically, LDAH acts antagonistically with PNPLA2/ATGL by enhancing the ubiquitination and proteasomal degradation of this key triglyceride lipase, thereby reducing triglyceride turnover 2. In macrophages, LDAH demonstrates weak cholesterol esterase activity and promotes cholesterol efflux, with high expression observed in macrophage-rich areas of atherosclerotic lesions 1. Recent studies suggest LDAH protects against atherosclerosis by mobilizing liver X receptor sterol ligands and modulating macrophage activation toward a less inflammatory phenotype 3. Clinically, LDAH expression is associated with various cancers, with decreased expression linked to poor survival in ovarian and pancreatic cancers 45, and genetic variants associated with prostate cancer risk 6.