For Lxr target genes Abca1, Scd1 and Srebf1 (encodes for sterol regulatory element binding protein 1c (Srebp1c)), a similar discrepancy as was seen for their small intestinal gene expression on a high-fat diet was reflected in the susceptibility of the corresponding null mice to develop obesity and/or insulin resistance (Table 1). This evidence concerns the gene ABCA1 and obesity due to melanocortin 4 receptor deficiency.