Author: Nat Pernick, M.D.

Revised: 7 May 2018, last major update July 2013

Copyright: (c) 2003-2018,, Inc.

PubMed Search: CDK4[title]
Cite this page: Pernick, N. CDK4. website. Accessed October 17th, 2018.
Definition / general
  • Complex is key regulator of transition through G1 phase of cell cycle (Genes Cancer 2012;3:658)
  • Also called Cyclin-dependent kinase 4
  • Among cyclin/CDKs, CDK4 and cyclin D1 are the most frequently activated by somatic genetic alterations in multiple tumor types (Proc Natl Acad Sci USA 2009;106:4166)
  • Well differentiated and dedifferentiated family of liposarcomas demonstrates amplification of chromosome subregion 12q13-q15 with resultant amplification of MDM2 and CDK4 genes
Diagrams / tables

Images hosted on other servers:

CDK4 binds with cyclin D

CDK4 regulation and activation

Clinical features
Uses by pathologists
Microscopic (histologic) images

Images hosted on other servers:

Breast carcinoma

Liposarcoma - dedifferentiated (left), well differentiated (right)

Images hosted on Flickr:

Breast carcinoma

Positive stains
  • Atypical lipomatous tumor / well differentiated liposarcoma (due to amplification of MDM2 and CDK4)
  • Dedifferentiated liposarcoma arising from atypical lipomatous tumor / well differentiated liposarcoma
  • Dedifferentiated liposarcoma with meningothelial-like whorls (Am J Surg Pathol 2011;35:356)
  • Low grade osteosarcomas (Mod Pathol 2011;24:624) and high grade osteosarcomas that progressed from low grade osteosarcomas (Am J Surg Pathol 2012;36:423)
  • Some cases of undifferentiated high grade pleomorphic sarcoma (Am J Surg Pathol 2009;33:1594)
Negative staining
  • Carcinoma, lymphoma, sarcomas other than atypical lipomatous tumor / well differentiated liposarcoma (or dedifferentiated liposarcoma arising from it)