Once an organ is formed, it is maintained by multiple mechanisms that may be exploited for self-microfabrication. Under normal physiological conditions, also called steady-state homeostasis, tissues use specific maintenance strategies to function throughout the lifetime of an organism 356 (Table ). Other strategies may be activated following a perturbation, such as regeneration in injuries, dysfunctions, pathologies or aging . This diversity of available tissue maintenance strategies, often within a single organ, can be exploited to grow organoids of interest. For instance, many organoids rely on ASC-mediated tissue renewal , such as the hair bulge, basal keratinocytes or intestinal crypts 356 . Other organs are maintained by progenitor cells with restricted self-renewal, or terminally differentiated cells that revert to proliferation 405 . Others leverage dedifferentiation or transdifferentiation, such as hepatocytes upon chronic injuries . A few tissues have little to no cell turnover, such as most post-mitotic neurons or the inner ear hair cells 390 , and may rely on increased intracellular repair mechanisms to maintain their function 391 . Other non-proliferative strategies, such as cell compensations for metabolism, size or shape help maintain the organ function 407 ; for instance, physical exercise induces skeletal muscle cell hypertrophy 394 . Some organs use more than one tissue maintenance strategy, the liver being a prime example. Hepatocytes use cell proliferation during steady-state homeostasis. Following the surgical removal of 30% of the liver, hepatocytes activate compensatory hypertrophy, and following other injuries like toxin exposure, they can transdifferentiate or recruit progenitor cells 370 . Switching from one mechanism to the next can be either preprogrammed within cells, or triggered by external signals, such as apoptosis 405 , phagocytosis, ECM remodeling, and inflammation. Surrounding cells can also signal what tissue maintenance strategy to use, such as macrophages 408 , adipocytes 409 , or microbes 410 . These signals can be induced in culture and engineered to enable tissue growth in non-regenerative organs . Thus, self-microfabrication is conceivable even in non-regenerative organs.