Xiaowei (George) Xu, MD, PhD

Professor of Pathology and Laboratory Medicine at the Hospital of the University of Pennsylvania
Professor of Dermatology
University of Pennsylvania Perelman School of Medicine

Contact InformationHospital of the University of Pennsylvania
Department of Pathology and Laboratory Medicine
6 Founders Pavilion
Philadelphia, PA 19104-4283
Office: 215-662-6503
Fax: 215-349-5910


Specialty Division

Anatomic Pathology, Immunobiology and Experimental Pathology

Research Expertise

Skin stem cells and melanoma

Clinical Expertise

Pigmented lesion, vasculitis, dermatopathology

Itmat Expertise

Dr. Xu's lab studies skin adult stem cell, melanocyte and melanoma biology with aims to effective therapies for vitiligo, melasma, melanoma and other skin conditions.


MD (Medicine), Fudan University School of Medicine, Shanghai, China, 1992
PhD (Pharmacology), Wake Forest University School of Medicine, Winston-Salem, NC, 1996

Specialty Certification

American Board of Pathology (Anatomic and Clinical Pathology), 2001
American Board of Pathology and Dermatology (Dermatopathology), 2002

Postgraduate Training

Postdoctoral Fellowship, Department of Physiology and Pharmacology, Dr. William Sonntag's Lab, Wake Forest University, Winston Salem, NC, 1996-1997
Resident in Anatomic and Clinical Pathology, Department of Pathology and Laboratory Medicine, University of Pennsylvania School of Medicine, Philadelphia, PA, 1997-2001
Postdoctoral Fellowship, Department of Dermatology, Dr. George Cotsarelis' Lab, University of Pennsylvania, Philadelphia, PA, 1999-2001
Clinical Fellowship in Dermatopathology, Harvard Medical School, Boston, MA, 2001-2002

Awards and Honors

Scholarship from Shanghai Medical, Shanghai China University Youth Research Funds, 1988-1990
Glenn Foundation Scholar Award from The American Federation For Aging Research., 1994-1994
Glenn Foundation Endocrinology and Aging Award, 1997-1997
Travel grant from American Association for Cancer Research, Inc., 1998
Warren R. Lang award for resident physician best scientific paper from American Society of Cytopathology, 2000
Stowell-Orbison award for resident physician best scientific paper from United States and Canadian Academy of Pathology, 2002
McCabe fellowship, University of Pennsylvania, 2003
America's Top Doctors, 2017
Top Doctors 2018, Philadelphia magazine, 2018
Clinical Research 2019 Top Ten Finalists by Clinical Research Forum, 2019
Top Doctors 2019, Philadelphia magazine, 2019
Highly Cited Researcher, Web of Science, Clarivate, 2020
Distinguished Pathologist Award, Chinese American Pathologists Association, 2020
Top Doctors 2020, Philadelphia magazine, 2020
Top Doctors 2021, Philadelphia magazine, 2021
Highly Cited Researcher, Web of Science, Clarivate, 2021

Memberships and Professional Organizations

American Cancer Society, 2004 - 2006
Society for Melanoma Research, 2004 - 2014
International Society of Stem Cell Research, 2004 - 2006
American Society of Investigative Pathology, 2006 - 2010
United States and Canadian Academy of Pathology, 2007 - 2012
Plexxicon, 2007 - 2009
Chinese National Science Foundation, 2007 - 2013
Hoffmann-La Roche Inc, 2009 - 2009
VA Merit award review, RRD0 R, 2009 - 2009
NIH study section, ZRG1 VH-E 10, 2009 - 2009
Scottish Chief Scientist Office, 2010 - 2015
Scientific Merit Review Board, Department of Veterans Affairs Rehabilitation Research and Development Service., 2010 - 2014
NIH study section (ZRG1 VH-F 02), 2010 - 2010
VA Merit award review, RRD0 R, 2010 - 2010
Melanoma Research Foundation, 2012 - Present
NIH study section (RPRB-B (O1)), 2014 - 2014
NIH Study section, special emphasis panel (SEP-9), 2014 - 2014
The North American Chinese Dermatologist Association, 2015 - 2019
NCI study section, 2016/01 ZCA1 RPRB-B (J1) P, 2015 - 2015
NCI review, Targeted Radionuclide Therapy, 2015 - 2015
Chinese National Natural Science Foundation of China, 2016 - 2019
Chinese National Science Foundation of China, 2017 - 2019
NIH study section, ZCA1 SRB-J (M4), 2017 - 2017
NCI SPORE III Review Committee, 2018 - 2018
NCI Study Section (ZCA1 TCRB-3 C1 B, TEP-1A), 2019 - 2019
NIH 2021 ZRG1 OTC1-J (55), 2021 - 2021

Selected Publications

Generation of melanocytes from Induced pluripotent stem cells

Yang R, Jiang M, Kumar SM, Xu T, Wang F, Xiang L, Xu X, J Invest Dermatol 131(12): 2458-66, 2011

Isolation of neural crest stem cells from human hair follicles

Yang R, Xu X, J Vis Exp 74(): 3194, 2013, PMID:23608752

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A Phase II, Open Label, Single-arm Trial of Imatinib Mesylate in Patients with Metastatic Melanoma Harboring c-Kit Mutation or Amplification

Guo J, Si L, Kong Y, Flaherty KT, Xu X, Zhu Y, Corless CL, Li L, Li H, et al, J Clin Onco 29(21): 2904-9, 2011

High Lymphatic Vessel Density and Lymphatic Invasion Underlie the Adverse Prognostic Effect of Radial Growth Phase Regression in Melanoma

Yun SJ, Gimotty PA, Hwang WT, Dawson P, Van Belle P, Elder DE, Elenitsas R, Schuchter L, Guerry D, Xu X, Am J Surg Path 35(3): 235-42, 2011

Stem Cells with Neural Crest Characteristics Derived from the Bulge Region of Cultured Human Hair Follicles

Yu H, Kumar SM, Kossenkov AV, Showe L, Xu X, J Invest Dermatol 130(5): 1227-36, 2010

Clinical efficacy of a RAF inhibitor requires comprehensive ERK pathway inhibition in BRAF-mutant melanoma

Bollag G, Hirth P, Tsai J, Zhang J, Ibrahim PN, Cho H, Spevak W, Zhang C, Zhang Y, Habets G, Burton B, West BL, Powell B, Shellooe R, Marimuthu A, Nguyen H, Zhang KYJ, Artis DR, Schlessinger J, Su F, Higgins B, Iyer R, D’Andrea K, Koehler A, Stumm M, Lee RJ, Grippo J, Puzanov I, Kim KB, Ribas A, McArthur GA, Sosman JA, Chapman PB, Flaherty KT, Xu X, Nathanson KL, Nolop K, Nature 467(7315): 596-9, 2010

Acquired resistance to BRAF inhibitors mediated by an A/B/C RAF kinase switch in melanoma can be overcome by co-targeting MEK and IGF-1R/PI3K

Villanueva J, Vultur A, Lee JT, Somasundaram R, Fukunaga-Kalabis1 M, Cipolla1 AK, Wubenhorst B, Xu X, Gimotty PA, Kee D, Santiago-Walker1 AE, Letrero R, Pushparajan A, Hayden JE, Laquerre S, McArthur GA, Sosman JA, Nathanson KL, Herlyn M, Cancer Cell 18(6): 683-95, 2010

Melanocyte stem cells can be isolated from the human dermis.

Li, L., Fulunaga-Kalabis, M., Yu, H., Xu, X., Kong, J., Lee, J.T. Herlyn, M.:, J Cell Sci 123(6): 853-60, 2010

Suppression of human prostate tumor growth by a prostate-specific monoclonal antibody F77 targeting a unique cell surface marker

Zhang G, Zhang H, Wang Q, Lal P, Carroll A, de la Llera-Moya M, Xu X, Greene MI., Proc Natl Acad Sci U S A 107(2): 732-7, 2010

Isolation of a novel population of multipotent adult stem cells from human hair follicles

Yu H., Fang D., Kumar SM., Li L., Nguyen TK., Acs G., Herlyn M., Xu X., American Journal of Pathology 168(6): 1879-88, 2006, PMID:16723703

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