This looks like an interesting effort to measure the effect of drugs on genes and tie the results to what is known about the genetics of diseases.
The Connectivity Map: using gene-expression signatures to connect small molecules, genes, and disease.
Science. 2006 Sep 29;313(5795):1929-35.
Lamb J, Crawford ED, Peck D, Modell JW, Blat IC, Wrobel MJ, Lerner J, Brunet JP, Subramanian A, Ross KN, Reich M, Hieronymus H, Wei G, Armstrong SA, Haggarty SJ, Clemons ...