Nakata et al. Journal of Experimental & Clinical Cancer Research 2010, 29:15 http://www.jeccr.com/content/29/1/15 Page 7 of 7 in patients with solid tumor malignancies. J Clin Oncol 2000, 18:3553-3557. 18. Pressacco J, Mitrovski B, Erlichman C, Hedley DW: Effects of thymidylate synthase inhibition on thymidine kinase activity and nucleoside transporter expression. Cancer Res 1995, 55:1505-1508. 19. Nakahira S, Nakamori S, Tsujie M, Takeda S, Sugimoto K, Takahashi Y, Okami J, Marubashi S, Miyamoto A, Takeda Y, Nagano H, Dono K, Umeshita K, Sakon M, Monden M: Pretreatment with S-1, an oral derivative of 5-fluorouracil, enhances gemcitabine effects in pancreatic cancer xenografts. Anticancer Res 2008, 28:179-186. doi:10.1186/1756-9966-29-15 Cite this article as: Nakata et al.: Plasma pharmacokinetics after combined therapy of gemcitabine and oral S-1 for unresectable pancreatic cancer. Journal of Experimental & Clinical Cancer Research 2010 29:15. Submit your next manuscript to BioMed Central and take full advantage of: • Convenient online submission • Thorough peer review • No space constraints or color ﬁgure charges • Immediate publication on acceptance • Inclusion in PubMed, CAS, Scopus and Google Scholar • Research which is freely available for redistribution Submit your manuscript at www.biomedcentral.com/submit