Abstract: The present invention provides compositions and methods to assess the state of a reverse cholesterol transport (RCT). In one aspect of the invention provides methods, compositions and kits for diagnosing a subject with deficient reverse cholesterol transport (RCT). In another aspect, the present invention provides a method of identifying responders to RCT treatment. In yet another aspect, the present invention provides a method of treating a subject with RCT deficiency. Also provided by the present invention is a method for drug screening and/or assessing risk of toxicity associated with RCT treatments.