The drug with the lowest (best) IC50 was Thiostrepton (IC50 = 3.95 ± 0.02 x 10−6 M), a cyclic oligopeptide used as a topical antibiotic in animals that interacts with the transcription factor FOXM1 to inhibit the growth of breast cancer cells in vitro (Hegde et al., 2011). The gene discussed is FOXM1; the disease is breast carcinoma.