Ye et al. BMC Cancer 2010, 10:611 http://www.biomedcentral.com/1471-2407/10/611 Conclusions Plexin-B1 was strongly expressed in tissues of patients with ovarian serous adenocarcinomas and its expression was found to be associated with lymph node metastasis. In vitro assays indicated that Plexin-B1 contributes to tumor migration and invasion. Additional studies are warranted to elucidate the role of Plexin-B1 as a possi- ble tumor marker as well as a putative therapeutic target for ovarian serous tumors. Abbreviations siRNA: short interference RNA; AKTSer-473: AKT at serine 473; Sema 4D: semaphorin 4D. Acknowledgements This work was supported by the National Natural Science Foundation of China (grant No. 30528012) and the “973” Program of China (grant No. 2002CB513100). Author details 1Cancer Biology Research Center, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, 430030, China. 2Department of Gynecology, Yantai Yuhuangding Hospital, affiliated to Qingdao University Medical College, Yantai, Shandong, 264000, China. Authors’ contributions SY carried out the immunohistological staining, participated in functional assays and drafted the manuscript. XH carried out SKOV3 cell proliferation changes upon Plexin-B1 silencing; performed assays to detect the effect of Plexin-B1 siRNA2 on the migration, invasion and cytoskeleton of SKOV3 cells; and revised the manuscript. TZ, MW and JW designed the study. YW and LZ guided and helped SY in the immunohistochemical staining and analyzed the immunohistochemical data. XJ and LJ supported the molecular studies and data analysis. YC and LY participated in the design of the study and provided expertise in molecular biological techniques. 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