The present invention relates to compositions for use in raising or lowering the level of LIPG polypeptide in a patient. Embodiments of the composition include compositions comprising: an anti-sense nucleic acid; a neutralizing antibody; an intracellular binding protein; an inhibitor which inhibits the enzymatic activity of LIPG polypeptide; an inhibitor which inhibits the expression of LIPG gene; a ribozyme; an LIPG polypeptide; an enhancer which increases the enzymatic activity of LIPG polypeptide; or an enhancer which increases the expression of LIPG gene. The invention relates also to methods for using the above compositions. In addition, the invention relates to a method for diagnosing a predisposition to lower cholesterol, a method for determining whether a test compound can inhibit the enzymatic reaction between LIPG polypeptide and HDL cholesterol, and methods for determining whether a test compound can enhance the enzymatic reaction between LIPG polypeptide and LDL or VLDL cholesterol.