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Genetics Home Reference: your guide to understanding genetic conditions     A service of the U.S. National Library of Medicine®


Reviewed April 2009

What is the official name of the RB1 gene?

The official name of this gene is “retinoblastoma 1.”

RB1 is the gene's official symbol. The RB1 gene is also known by other names, listed below.

What is the normal function of the RB1 gene?

The RB1 gene provides instructions for making a protein called pRB. This protein acts as a tumor suppressor, which means that it regulates cell growth and keeps cells from dividing too fast or in an uncontrolled way. Under certain conditions, pRB stops other proteins from triggering DNA replication, the process by which DNA makes a copy of itself. Because DNA replication must occur before a cell can divide, tight regulation of this process controls cell division and helps prevent the growth of tumors. Additionally, pRB interacts with other proteins to influence cell survival, the self-destruction of cells (apoptosis), and the process by which cells mature to carry out special functions (differentiation).

Does the RB1 gene share characteristics with other genes?

The RB1 gene belongs to a family of genes called endogenous ligands (endogenous ligands).

A gene family is a group of genes that share important characteristics. Classifying individual genes into families helps researchers describe how genes are related to each other. For more information, see What are gene families? ( in the Handbook.

How are changes in the RB1 gene related to health conditions?

retinoblastoma - increased risk from variations of the RB1 gene

Hundreds of mutations in the RB1 gene have been identified in people with retinoblastoma, a rare type of eye cancer that typically affects young children. This cancer develops in the retina, which is the specialized light-sensitive tissue at the back of the eye that detects light and color. Researchers estimate that 40 percent of all retinoblastomas are germinal, which means that RB1 mutations occur in all of the body's cells and can be passed to the next generation. The other 60 percent are non-germinal, which means that RB1 mutations occur only in the eye and cannot be passed to the next generation.

In germinal retinoblastoma, an RB1 mutation is present in all of the body's cells. For retinoblastoma to develop, the other copy of the RB1 gene also must be mutated or lost. This second mutation typically occurs early in life in retinal cells. Cells with two altered copies of the RB1 gene produce no functional pRB and are unable to regulate cell division effectively. As a result, retinal cells lacking functional pRB can divide uncontrollably to form cancerous tumors. Some studies suggest that additional genetic changes can influence the development of retinoblastoma; these changes may help explain variations in the development and growth of tumors in different people.

In people with germinal retinoblastoma, RB1 mutations increase the risk of several other cancers outside the eye. Specifically, these people are more likely to develop a cancer of the pineal gland in the brain (pinealoma), a type of bone cancer known as osteosarcoma, cancers of soft tissues such as muscle, and an aggressive form of skin cancer called melanoma.

Non-germinal retinoblastoma occurs in people with no history of the disorder in their family. Affected individuals are born with two normal copies of the RB1 gene. Then, usually in early childhood, both copies of the gene in retinal cells acquire mutations or are lost. These genetic changes prevent the cells from producing any functional pRB. The loss of this protein allows retinal cells to grow and divide without control or order, leading to the development of a cancerous tumor.

bladder cancer - associated with the RB1 gene

Some gene mutations are acquired during a person's lifetime and are present only in certain cells. These changes, which are called somatic mutations, are not inherited. Somatic mutations that turn off (inactivate) the RB1 gene have been reported in some cases of bladder cancer. Mutations in RB1 are thought to contribute to the development of bladder cancer, and these genetic changes may help predict whether tumors will grow rapidly and spread to other tissues.

other cancers - associated with the RB1 gene

In addition to bladder cancer, somatic mutations in the RB1 gene are associated with many other types of cancer. For example, changes in the RB1 gene have been reported in some cases of lung cancer, breast cancer, a bone cancer known as osteosarcoma, and an aggressive form of skin cancer called melanoma. Somatic RB1 mutations have also been identified in some leukemias, which are cancers of blood-forming cells. Somatic RB1 mutations in cancer cells inactivate pRB so it can no longer regulate cell division effectively.

Where is the RB1 gene located?

Cytogenetic Location: 13q14.2

Molecular Location on chromosome 13: base pairs 48,303,747 to 48,481,890

(Homo sapiens Annotation Release 107, GRCh38.p2) (NCBI (

The RB1 gene is located on the long (q) arm of chromosome 13 at position 14.2.

The RB1 gene is located on the long (q) arm of chromosome 13 at position 14.2.

More precisely, the RB1 gene is located from base pair 48,303,747 to base pair 48,481,890 on chromosome 13.

See How do geneticists indicate the location of a gene? ( in the Handbook.

Where can I find additional information about RB1?

You and your healthcare professional may find the following resources about RB1 helpful.

You may also be interested in these resources, which are designed for genetics professionals and researchers.

What other names do people use for the RB1 gene or gene products?

  • p105-Rb
  • PP110
  • PPP1R130
  • RB
  • RB1 gene
  • Retinoblastoma-1
  • Retinoblastoma 1 (including osteosarcoma)
  • Retinoblastoma-associated protein

See How are genetic conditions and genes named? ( in the Handbook.

What glossary definitions help with understanding RB1?

apoptosis ; cancer ; cell ; cell division ; differentiation ; DNA ; DNA replication ; gene ; inherited ; melanoma ; mutation ; osteosarcoma ; pineal ; pineal gland ; pinealoma ; protein ; retina ; tissue ; transcription ; tumor

You may find definitions for these and many other terms in the Genetics Home Reference Glossary.


  • Classon M, Harlow E. The retinoblastoma tumour suppressor in development and cancer. Nat Rev Cancer. 2002 Dec;2(12):910-7. Review. (
  • de Andrade AF, da Hora Barbosa R, Vargas FR, Ferman S, Eisenberg AL, Fernandes L, Bonvicino CR. A molecular study of first and second RB1 mutational hits in retinoblastoma patients. Cancer Genet Cytogenet. 2006 May;167(1):43-6. (
  • Du W, Pogoriler J. Retinoblastoma family genes. Oncogene. 2006 Aug 28;25(38):5190-200. Review. (
  • Goodrich DW. The retinoblastoma tumor-suppressor gene, the exception that proves the rule. Oncogene. 2006 Aug 28;25(38):5233-43. Review. (
  • Herwig S, Strauss M. The retinoblastoma protein: a master regulator of cell cycle, differentiation and apoptosis. Eur J Biochem. 1997 Jun 15;246(3):581-601. Review. (
  • Knudsen ES, Knudsen KE. Retinoblastoma tumor suppressor: where cancer meets the cell cycle. Exp Biol Med (Maywood). 2006 Jul;231(7):1271-81. Review. (
  • Korabiowska M, Ruschenburg I, Betke H, Stachura J, Schlott T, Cardo CC, Brinck U. Downregulation of the retinoblastoma gene expression in the progression of malignant melanoma. Pathobiology. 2001;69(5):274-80. (
  • Leiderman YI, Kiss S, Mukai S. Molecular genetics of RB1--the retinoblastoma gene. Semin Ophthalmol. 2007 Oct-Dec;22(4):247-54. Review. (
  • Liu H, Dibling B, Spike B, Dirlam A, Macleod K. New roles for the RB tumor suppressor protein. Curr Opin Genet Dev. 2004 Feb;14(1):55-64. Review. (
  • Lohmann DR, Gallie BL. Retinoblastoma: revisiting the model prototype of inherited cancer. Am J Med Genet C Semin Med Genet. 2004 Aug 15;129C(1):23-8. Review. (
  • NCBI Gene (
  • Richter S, Vandezande K, Chen N, Zhang K, Sutherland J, Anderson J, Han L, Panton R, Branco P, Gallie B. Sensitive and efficient detection of RB1 gene mutations enhances care for families with retinoblastoma. Am J Hum Genet. 2003 Feb;72(2):253-69. Epub 2002 Dec 18. (
  • Sampieri K, Hadjistilianou T, Mari F, Speciale C, Mencarelli MA, Cetta F, Manoukian S, Peissel B, Giachino D, Pasini B, Acquaviva A, Caporossi A, Frezzotti R, Renieri A, Bruttini M. Mutational screening of the RB1 gene in Italian patients with retinoblastoma reveals 11 novel mutations. J Hum Genet. 2006;51(3):209-16. Epub 2006 Feb 4. (
  • Wolff EM, Liang G, Jones PA. Mechanisms of Disease: genetic and epigenetic alterations that drive bladder cancer. Nat Clin Pract Urol. 2005 Oct;2(10):502-10. Review. (


The resources on this site should not be used as a substitute for professional medical care or advice. Users seeking information about a personal genetic disease, syndrome, or condition should consult with a qualified healthcare professional. See How can I find a genetics professional in my area? ( in the Handbook.

Reviewed: April 2009
Published: February 8, 2016