This microarray contains the sequences from 10,000 human genes developed in Pat Brown’s laboratory in our department.  In this experiment, Doug Ross took  RNA from promyelocytes in patients with acute promyelocytic leukemia was copied and labeled with a RED fluorescent compound. The Red spots show which human genes are expressing RNA in the promyelocytic tumor cells. 

Acute promyelocytic leukemia results from a translocation in which the gene controlling differentiation of the promyelocytes now comes under the regulatory control of a retinoic Acid receptor. Treating patients with retinoic acid results in the tumor cells halting growth and differentiating into normal promyelocytes.  In this experiment,