PLA2G1B (phospholipase A2 group IB) is a secretory calcium-dependent enzyme that primarily functions in lipid metabolism within the intestinal tract 1. The enzyme catalyzes the hydrolysis of phospholipids at the sn-2 position, with substrate preference for phosphatidylethanolamines and phosphatidylglycerols over phosphatidylcholines 1. PLA2G1B plays a crucial role in dietary lipid digestion, producing lysophospholipids that directly mediate chylomicron assembly and secretion 2. The enzyme's metabolic products contribute significantly to cardiometabolic diseases, as lysophosphatidylcholine and lysophosphatidic acid absorbed through the digestive tract promote systemic inflammation and cardiovascular dysfunction 2. Beyond digestive functions, PLA2G1B demonstrates diverse pathophysiological roles. In respiratory diseases, it regulates cellular energy metabolism in COPD, where its downregulation in epithelial cells triggers inflammation, oxidative stress, and apoptosis 3. The enzyme shows promise as a biomarker across multiple cancers, with higher expression associated with favorable prognosis in prostate cancer 4 and potential preventive effects in lung cancer 5. Additionally, PLA2G1B participates in immune regulation, where microbial proteins can enhance its enzymatic activity through gC1qR binding, leading to CD4 T-cell anergy in various infectious diseases 6.