Composition to reduce lipg gene expulsion and the enzymatic activity of the lipg polypeptide, to inhibit the enzymatic activity of the lipg polypeptide, to increase the level and enzymatic activity of the lipg polypeptide in a patient and methods to increase the cholesterol level of high density lipoprotein and apolipoprotein ai, to reduce the level of very low density lipoprotein cholesterol and ldl cholesterol and vldl cholesterol in a patient, to diagnose a predisposition to low levels of hdl cholesterol and apolipoprotein ai, and to determine whether a test compound can inhibit the enzymatic reaction between lipg polypeptide and hdl cholesterol and apolipoprotein ai and can increase the enzymatic reaction between lipg polypeptide and vldl and vdl cholesterol