APMAP (adipocyte plasma membrane-associated protein) is a paraoxonase-like enzyme with multiple tissue-specific functions. In adipose tissue, APMAP is upregulated during adipogenesis in a PPARγ-dependent manner and is required for proper adipocyte differentiation, with its extracellular C-terminal domain critical for this function 1. At the molecular level, APMAP exhibits arylesterase activity and interacts with extracellular matrix proteins lysyl oxidase-like 1 and 3, regulating collagen cross-linking and fibrotic potential in adipose tissue 2. APMAP functions as an endoplasmic reticulum (ER)-localized antioxidant that suppresses ER lipid oxidation through paraoxonase-like activity, maintaining lipid and lipoprotein homeostasis 3. In cancer, APMAP is a cancer-intrinsic regulator of susceptibility to antibody-dependent cellular phagocytosis (ADCP); loss of APMAP synergizes with monoclonal antibodies and CD47-blocking agents to enhance macrophage-mediated phagocytosis across multiple cancer types 4. In the brain, APMAP associates with γ-secretase and modulates amyloid-β production through interactions with autophagy-lysosome pathway components 5. Recent evidence demonstrates APMAP's role in esophageal squamous cell carcinoma, where ER stress-induced CRELD2 promotes APMAP membrane localization, activating TGF-β/SMAD and NF-κB signaling 6. N-glycosylation at N196 of APMAP is implicated in colorectal cancer metabolism and progression 7.