Interests. Authors’ contributions PAH performed the research; PAH and NHD created the analysis study, analyzed the information, and wrote the paper; KO, SI and CM contributed critical reagents and analyzed the information; LHD analyzed the information and critically revised the paper. All authors read and approved the final manuscript. Acknowledgements We thank Neal Benson, Director of your Flow Cytometry core in the Interdisciplinary Center for Biotechnology Study at the University of Florida. Author details 1 Division of Hematology/Oncology, University of Florida Shands Cancer Center, Gainesville, FL 32610, USA. 2Department of Therapy Development and Innovation for Immune Disorders and Cancers, Graduate College of Medicine, Juntendo University, Tokyo 113-8421, Japan. 3Division of Hematology/Oncology, University of Florida, 1600 SW Archer Road, Box 100278, Gainesville, Florida 32610, USA. Received: 12 June 2013 Accepted: 30 October 2013 Published: 1 November 2013 References 1. Pang R, Law WL, Chu AC, Poon JT, Lam CS, Chow AK, Ng L, Cheung LW, Lan XR, Lan HY, et al: A subpopulation of CD26+ cancer stem cells with8.9.10.11.12.13.14.15.16.17.18.19.20.metastatic capacity in human colorectal cancer. Cell Stem Cell 2010, six(6):603?15. de Andrade CF, Bigni R, Pombo-de-Oliveira MS, Alves G, Pereira DA: CD26/ DPPIV cell membrane expression and DPPIV activity in plasma of sufferers with acute leukemia. J Enzyme Inhib Med Chem 2009, 24(3):708?14. De Chiara L, Rodriguez-Pineiro AM, Rodriguez-Berrocal FJ, Cordero OJ, Martinez-Ares D, Paez de la Cadena M: Serum CD26 is associated to histopathological polyp traits and behaves as a marker for colorectal cancer and sophisticated adenomas.3-Bromo-5-fluoro-4-methylbenzoic acid custom synthesis BMC Cancer 2010, 10:333.4,5-Dichloro-2-hydroxybenzaldehyde Chemscene Dohi O, Ohtani H, Hatori M, Sato E, Hosaka M, Nagura H, Itoi E, Kokubun S: Histogenesis-specific expression of fibroblast activation protein and dipeptidylpeptidase-IV in human bone and soft tissue tumours. Histopathology 2009, 55(4):432?40. Varona A, Blanco L, Perez I, Gil J, Irazusta J, Lopez JI, Candenas ML, Pinto FM, Larrinaga G: Expression and activity profiles of DPP IV/CD26 and NEP/ CD10 glycoproteins in the human renal cancer are tumor-type dependent. BMC Cancer 2010, ten:193. Wesley UV, McGroarty M, Homoyouni A: Dipeptidyl peptidase inhibits malignant phenotype of prostate cancer cells by blocking fundamental fibroblast development issue signaling pathway. Cancer Res 2005, 65(4):1325?334. Kajiyama H, Kikkawa F, Suzuki T, Shibata K, Ino K, Mizutani S: Prolonged survival and decreased invasive activity attributable to dipeptidyl peptidase IV overexpression in ovarian carcinoma.PMID:23771862 Cancer Res 2002, 62(ten):2753?757. Sato T, Yamochi T, Yamochi T, Aytac U, Ohnuma K, McKee KS, Morimoto C, Dang NH: CD26 regulates p38 mitogen-activated protein kinasedependent phosphorylation of integrin beta1, adhesion to extracellular matrix, and tumorigenicity of T-anaplastic substantial cell lymphoma Karpas 299. Cancer Res 2005, 65(15):6950?956. Ohnuma K, Yamochi T, Uchiyama M, Nishibashi K, Yoshikawa N, Shimizu N, Iwata S, Tanaka H, Dang NH, Morimoto C: CD26 up-regulates expression of CD86 on antigen-presenting cells by suggests of caveolin-1. Proc Natl Acad Sci USA 2004, 101(39):14186?4191. Fox DA, Hussey RE, Fitzgerald KA, Acuto O, Poole C, Palley L, Daley JF, Schlossman SF, Reinherz EL: Ta1, a novel 105 KD human T cell activation antigen defined by a monoclonal antibody. J Immunol 1984, 133(3):1250?256. Dang NH, Torimoto Y, Deusch K, Schlossman SF, Morimoto C: Comitogenic impact of solid-phase immobiliz.