Acetoacetic acid is an endogenous metabolite present in Cerebrospinal_Fluid and Blood that can be used for the research of Meningitis, Pregnancy, 3 Hydroxy 3 Methylglutaryl CoA Lyase Deficiency, Preeclampsia/Eclampsia, Diabetes Mellitus Type 2, Glucose Transporter Type 1 Deficiency Syndrome and Succinyl CoA:3 Oxoacid CoA Transferase Deficiency.