ABHD4 (abhydrolase domain containing 4) functions as a lysophospholipase with selectivity for N-acyl phosphatidylethanolamine (NAPE), contributing to endocannabinoid biosynthesis by hydrolyzing acyl chains from NAPE to generate intermediates for anandamide production 1. The enzyme shows broad substrate specificity for saturated, monounsaturated, and polyunsaturated N-acyl chains but lacks significant activity toward other lysophospholipids. ABHD4 plays critical roles in cellular lipid homeostasis and metabolism, with expression changes linked to various pathological conditions 23. Unlike its paralog ABHD5, ABHD4 cannot activate adipose triglyceride lipase (ATGL) due to specific structural differences, particularly lacking key amino acids (R299 and G328) required for lipase activation 45. Functionally, ABHD4 serves as a crucial mediator of developmental anoikis, a protective mechanism that eliminates pathologically detached progenitor cells in the developing brain while allowing normal neuroblast delamination 6. The enzyme's downregulation is necessary for daughter neuroblasts to escape anoikis during normal development. ABHD4 expression alterations are associated with acute coronary syndrome, colorectal cancer progression, and placental pathology in preeclampsia, suggesting broader clinical significance 237.