Microarray studies with breast cancer cells expressing DD1-ERT2 or DD1(S28A)-ERT2 incubated with or without 4-OHT identified the FASTKD2 gene as the pro-apoptotic gene that is rapidly expressed when DIF-1 mediated repression is reversed by the binding of NRIF3/DD1 [5]. The gene discussed is MAPK3; the disease is breast carcinoma.