Abstract: The invention provides a method for assessing or determining activity of a test Compound on modulation of gene product levels comprising culturing cells, contacting at least one of the cultured cells with a lipid-rich fraction, contacting at least one of the cultured cells with the test Compound, determining the presence of a gene product of at least one cell of the cultured cells and, optionally, determining the presence of the gene product of at least one cultured cell not contacted with the test Compound. To assess human conditions most fully, it is preferred that the cell is of human origin, for example, a peripheral blood monocyte taken from a healthy donor.