We previously injected human ovarian carcinoma SK-OV-3 cells into the peritoneum of female nude mice to establish an ovarian cancer xenograft mouse model.4 We then performed expression profiling to identify genes that were differentially expressed in the metastatic tissues, compared with the injected SK-OV-3 cells, from the xenograft mice.4, 5, 6, 7 Among the genes whose expression was altered more than twofold in metastatic tissues, we selected γ-aminobutyric acid (GABA)A receptor π subunit (GABRP), which was upregulated in the metastatic tissue, for further study. The gene discussed is GABRP; the disease is ovarian carcinoma.