División celular, crecemento e proliferación
A **proliferción celular** é o proceso polo cal *unha célula crece e se divide para producir dúas células fillas*. A proliferación celular leva a un exponencial no número de células e é, por tanto, un mecanismo rápido de crecemento dos tecidos. A proliferación celular require xeralmente un crecemento celular e a división celular, de tal maneira que o tamaño das células permanece constante na poboación de células. Nalgún casos, a división celular pode ocorrer sen crecemento celular, producindo células progresivamene máis pequenas (como na segmentación do cigoto nas primeiras fases embrionarias), pero tmén hai casos en que se produce crecemento celular sen división celular, orixinando unha célula máis grande (como no crecemento das neuronas). Por conseguinte, a proliferación celular no é sinónimo de crecemento celular nin de división celular, a pesar de que estes termos ás veces e usen indistintamente.

Stem cells undergo cell proliferation to produce proliferating "transit amplifying" daughter cells that later differentiate to construct tissues during normal development and tissue growth, during tissue regeneration after damage, or in cancer.

The total number of cells in a population is determined by the rate of cell proliferation minus the rate of cell death.

Cell size depends on both cell growth and cell division, with a disproportionate increase in the rate of cell growth leading to production of larger cells and a disproportionate increase in the rate of cell division leading to production of many smaller cells. Cell proliferation typically involves balanced cell growth and cell division rates that maintain a roughly constant cell size in the exponentially proliferating population of cells. Cell proliferation occurs by combining cell growth with regular "G1-S-M-G2" cell cycles to produce many diploid cell progeny.

In single-celled organisms, cell proliferation is largely responsive to the availability of nutrients in the environment (or laboratory growth medium).

In multicellular organisms, the process of cell proliferation is tightly controlled by gene regulatory networks encoded in the genome and executed mainly by transcription factors including those regulated by signal transduction pathways elicited by growth factors during [[cell signaling|cellModelo:Ndashcell communication]] in development. Recently it has been also demonstrated that cellular bicarbonate metabolism, which is responsible for cell proliferation, can be regulated by mTORC1 signaling.  In addition, intake of nutrients in animals can induce circulating hormones of the Insulin/IGF-1 family, which are also considered growth factors, and that function to promote cell proliferation in cells throughout the body that are capable of doing so.

Uncontrolled cell proliferation, leading to an increased proliferation rate, or a failure of cells to arrest their proliferation at the normal time, is a cause of cancer.

Notas
-----

1. ↑  Conlon, Ian; Raff, Martin (1999). "Size Control in Animal Development". *Cell* **96** (2): 235–244. ISSN 0092-8674. PMID 9988218. doi:10.1016/S0092-8674(00)80563-2.  Parámetro descoñecido `|s2cid=` ignorado (Axuda)
2. ↑  Grewal, Savraj S; Edgar, Bruce A (2003). "Controlling cell division in yeast and animals: does size matter?". *Journal of Biology* **2** (1): 5. ISSN 1475-4924. PMC 156596. PMID 12733996. doi:10.1186/1475-4924-2-5.
3. ↑  Neufeld, Thomas P; de la Cruz, Aida Flor A; Johnston, Laura A; Edgar, Bruce A (1998). "Coordination of Growth and Cell Division in the Drosophila Wing". *Cell* **93** (7): 1183–1193. ISSN 0092-8674. PMID 9657151. doi:10.1016/S0092-8674(00)81462-2.
4. 1 2  Thompson, Barry J. (2010). "Developmental control of cell growth and division in Drosophila". *Current Opinion in Cell Biology* **22** (6): 788–794. PMID 20833011. doi:10.1016/j.ceb.2010.08.018.
5. ↑  Saucedo, L (2002). "Why size matters: altering cell size". *Current Opinion in Genetics & Development* **12** (5): 565–571. ISSN 0959-437X. PMID 12200162. doi:10.1016/S0959-437X(02)00341-6.
6. ↑  Ali ES, Liponska A, O'Hara B, Amici D, Torno M, Gao P, Asara J, Yap M-N F, Mendillo M, Ben-Sahra I (June 2022). "The mTORC1-SLC4A7 axis stimulates bicarbonate import to enhance de novo nucleotide synthesis". *Molecular Cell* **82** (1): 1–15. doi:10.1016/j.molcel.2022.06.008.