GPD1 and hypertriglyceridemia: Other increased proteins include ANXA5, a phagocytic marker transcriptionally elevated after TBI, and glycerol-3-phosphate dehydrogenase 1 (GPD1), an enzyme involved in triglyceride metabolism and the cause of transient infantile hypertriglyceridemia.43 Finally, we observed higher abundance of several members of the serpin family protease inhibitors (SERPINA1B, 1D, 1E, and 3K).