 Apo A-I binds to lipopolysaccharide or endotoxin, and has a major role in the anti-endotoxin function of HDL.In one study, a decrease in apo A1 levels was detected in schizophrenia patients' CSF, brain and peripheral tissues.Apolipoprotein A1 and APOE interact epistatically to modulate triglyceride levels in coronary heart disease patients.