GDPD5 is a glycerophosphodiester phosphodiesterase that functions as a six-transmembrane domain protein involved in cellular membrane dynamics and signaling regulation 1. The enzyme catalyzes the hydrolysis of deacylated glycerophospholipids to glycerol phosphate and alcohol, and specifically cleaves glycosylphosphatidylinositol (GPI) anchors from membrane-bound proteins 12. GDPD5 is stored in Weibel-Palade bodies of endothelial cells and released upon stimulation to modify the cell surface by removing GPI-anchored proteins like CD59, leading to increased complement deposition and enhanced inflammatory responses 2. In neuroblastoma, GDPD5 promotes cellular differentiation through GTPase signaling pathways and is associated with favorable clinical outcomes 3. However, GDPD5 also contributes to cancer progression in other contexts - it is overexpressed in colorectal and gastric cancers where it promotes chemoresistance, metastasis, and epithelial-to-mesenchymal transition 45. In breast cancer, GDPD5 silencing decreases cell proliferation, migration, and invasion while increasing glycerophosphocholine levels 6. The protein is widely expressed across human tissues and plays roles in choline phospholipid metabolism and autophagosome formation 17.