polyploid cell endopolyploid cell https://cellxgene.cziscience.com/cellguide/CL_0000417 Endopolyploid cells are a specialized cell type characterized by having multiple complete sets of chromosomes, far exceeding the amount found in typical diploid cells. The process known as endoreplication results in variant cycles of DNA replication without subsequent cell divisions, leading to an increase in cell volume, an alteration in gene expression, and polyploidy. These cells are commonly found throughout the plant and animal kingdoms, indicating their foundational role in organismal biology. Endopolyploid cells serve critical roles in maintaining an organism's biological system by regulating tissue growth and development, cellular differentiation, and physiological response to environmental stimuli. For instance, in plants, endopolyploidy serves as a mechanism for increased cell size leading to larger fruits and broader leaves. In animals, these cells are fundamental in liver regeneration. Therefore, their prominence in adaptive and developmental processes across diverse organisms reflects their evolutionary importance. Endopolyploid cells also play a role in pathological conditions, primarily cancer development, where endoreplication can lead to genomic instability resulting in malignant progression. However, these cells also possess inherent potential for therapeutic applications. For example, stimulating endoreplication in cancer cells can trigger senescence and reduction in tumor growth. Furthermore, endopolyploid cells can be harnessed for regenerative medicine purposes, as they have demonstrated potential for differentiation and tissue repair. (This extended description was generated by ChatGPT and reviewed by the CellGuide team, who added references, and by the CL editors, who approved it for inclusion in CL. It may contain information that applies only to some subtypes and species, and so should not be considered definitional.)