FoxO is a critical regulator of stem cell maintenance and immortality in Hydra.

Boehm AM, Khalturin K, Anton-Erxleben F, Hemmrich G, Klostermeier UC, Lopez-Quintero JA, Oberg HH, Puchert M, Rosenstiel P, Wittlieb J, Bosch TC. FoxO is a critical regulator of stem cell maintenance in immortal Hydra. Proceedings of the National Academy of Sciences. 2012 Nov 27;109(48):19697-702. https://doi.org/10.1073/pnas.1209714109