PNPLA7 is a lysophospholipase localized to the endoplasmic reticulum and mitochondrial-associated membranes that preferentially hydrolyzes unsaturated lysophosphatidylcholine (C18:1) to generate glycerophosphocholine 1. This enzymatic activity regulates hepatic choline and methionine metabolism, with PNPLA7 deficiency decreasing glycerophosphocholine, choline, and methionine cycle intermediates 1. PNPLA7 also modulates apolipoprotein E stability to facilitate VLDL secretion and lipid metabolism 2. Beyond lipid catabolism, PNPLA7 functions as a negative regulator of white adipose tissue browning by promoting Parkin-mediated mitophagy during cold challenge 3. Additionally, PNPLA7 suppresses macrophage classical (M1) activation through SIRT1/NF-κB and p38 MAPK pathways by hydrolyzing the pro-inflammatory lipid lysophosphatidylcholine 4. Clinically, PNPLA7 expression is reduced in hepatocellular carcinoma and serves as a diagnostic and prognostic biomarker in gastric, colorectal, and urological cancers, with higher expression associated with improved survival 156. These findings establish PNPLA7 as a multifunctional phospholipid-metabolizing enzyme linking lipid homeostasis, energy metabolism, and immune regulation.