Other anti-cancer compounds were rifabutin, an antibiotic effective against lung cancer cells, PNU-0251126, which correlated positively with drugs for leukemia treatment, the protein phosphatase 2A inhibitor cantharidin, which induces cell death, the anti-inflammatory steroid medrysone, the topoisomerase II inhibitor ellipticine, a potent antineoplastic agent, and the non-steroidal selective estrogen receptor (ER) modulator tamoxifen, used to treat ER-positive breast cancer. The gene discussed is ESR1; the disease is leukemia.