LPCAT4 (lysophosphatidylcholine acyltransferase 4) is a lysophospholipid acyltransferase localized to the endoplasmic reticulum that plays critical roles in phospholipid remodeling and cellular metabolism 1. The enzyme converts various lysophospholipids to their corresponding phospholipids, including lysophosphatidylcholine to phosphatidylcholine and lysophosphatidylethanolamine to phosphatidylethanolamine, preferring long-chain acyl-CoAs as substrates 2. LPCAT4 expression is upregulated during cellular differentiation and metabolic switches, where it maintains barrier function and cellular bioenergetics through lipid-protein kinase C signaling pathways 2. The enzyme is regulated by epigenetic mechanisms, with Setd2-mediated H3K36me3 modifications controlling LPCAT4 expression to modulate T cell differentiation and prevent autoimmune diseases 3. In cancer contexts, LPCAT4 functions as both a prognostic biomarker and therapeutic target, with altered expression linked to tumor progression in hepatocellular carcinoma through WNT/β-catenin signaling 4 and metabolic reprogramming in prostate cancer 5. Additionally, hepatic LPCAT4 overexpression shows therapeutic potential for type 2 diabetes by improving glucose metabolism and enhancing insulin secretion 6.