Stains & CD markers

Last author update: 20 February 2024
Last staff update: 20 February 2024

Copyright: 2002-2024,, Inc.

PubMed Search: p63

Sawsan Ismail, M.D., M.Sc.
John Yahya I. Elshimali, M.D.
Page views in 2023: 36,210
Page views in 2024 to date: 9,949
Cite this page: Ismail S, Elshimali JYI. p63. website. Accessed April 14th, 2024.
Definition / general
  • Transcription factor that is a member of the p53 gene family
  • Master regulator of epidermal keratinocyte proliferation and embryonic epidermal growth
Essential features
Diagrams / tables

Images hosted on other servers:
Structure of p63 molecule

Structure of p63 molecule

Clinical features
  • Investigate the primary origin of malignant tumors
  • In most cases, p63 can help exclude the diagnosis of invasive adenocarcinomas in the prostate and breast; however, there are exceptions
  • Mainly nuclear
  • Could demonstrate cytoplasmic expression in Z bands in skeletal muscle cells (Mod Pathol 2011;24:1320)
Uses by pathologists
Prognostic factors
Microscopic (histologic) description
  • Nuclear marker for myoepithelial cells in benign tumors and noninvasive malignancies
Microscopic (histologic) images

Contributed by John Yahya I. Elshimali, M.D., Andrey Bychkov, M.D., Ph.D.,
Jijgee Munkhdelger, M.D., Ph.D., Hind Nassar, M.D. and Cases #117, 191 and 209

Prostatic glands

Myoepithelial cells staining positive for p63

Prostatic adenocarcinoma

Endometrial adenocarcinoma

Mammary glands and ducts

Myoepithelial cells

Elongated tubular structures with chondroid fibrous stroma

Solid cell nests

p63+ in many follicles

Correlates with a loss of TTF1

Missing Image

Adenoid cystic carcinoma, solid

Missing Image Missing Image

Seromucinous hamartoma p63-, no myoepithelial cells, positive internal control

Missing Image

Nephrogenic adenoma (p63- / AMACR+)

Missing Image Missing Image

Adenocarcinoma (upper, p63- / AMACR+) and benign (lower, p63+ / AMACR-)

Missing Image

Intraductal papilloma with DCIS immunoprofile

Intraductal papilloma with DCIS, p63

Positive staining - normal
Positive staining - disease
Negative staining
Molecular / cytogenetics description
  • Encoded by the gene TP63 located on 3q27-29
  • Multidomain protein with more than 6 isoforms
  • Isoforms are generated through alternative splicing at the 3 site
  • Tetramer that has a DNA binding domain (DBD), an N terminal transcactivation domain (TA), a tetramerization domain (TD) and a transcription inhibitory domain following C terminal sterile alpha motif (SAM) (Mol Cell Biol 2002;22:8601, Mol Cell 1998;2:305)
Molecular / cytogenetics images

Images hosted on other servers:
Characterization of p63 isoform specific antibodies

Characterization of p63 isoform specific antibodies

Sample pathology report
  • Prostate, core needle biopsy, measuring 2 x 1 x 1 cm and tan-brown in color:
    • Benign prostatic hyperplasia (see comment)
    • Comment: Microscopic examination of the biopsy revealed the proliferation of prostatic glands lined by epithelial cells with no signs of atypia in the lining of epithelial cells. Immunohistochemistry demonstrated a strong nuclear expression of p63 in the basal cells of the hyperplastic glands. These features correlate with benign prostatic hyperplasia.    
Board review style question #1

Which of the statements below regarding p63 is true?

  1. Has only 3 isoforms
  2. Loss of p63 expression correlates with poor prognosis in urothelial carcinoma
  3. p63 is absent in squamous epithelial cells
  4. p63 is a marker for smooth muscle cells
Board review style answer #1
B. Loss of p63 expression correlates with poor prognosis in urothelial carcinoma. Answer A is incorrect because p63 has more than 6 isoforms. Answer C is incorrect because p63 is a marker for squamous epithelial cells. Answer D is incorrect because p63 is a marker for basal epithelial cells.

Comment Here

Reference: p63
Back to top
Image 01 Image 02