found the ovarian stem cells, a rare type of cells (0.014%) found in the ovary. they could be used as a treatment not only for infertility, but also for premature ovarian insufficiency. critical limb ischemia research is underway to develop various sources for stem cells, and to apply stem cell treatments for neurodegenerative diseases and conditions, diabetes, heart disease, and other conditions. research is also underway in generating organoids using stem cells, which would allow for further understanding of human development, organogenesis, and modeling of human diseases. in more recent years, with the ability of scientists to isolate and culture embryonic stem cells, and with scientists' growing ability to create stem cells using somatic cell nuclear transfer and techniques to create induced pluripotent stem cells, controversy has crept in, both related to abortion politics and to human cloning. hepatotoxicity and drug-induced liver injury account for a substantial number of failures of new drugs in development and market withdrawal, highlighting the need for screening assays such as stem cell-derived hepatocyte-like cells, that are capable of detecting toxicity early in the drug development process. notable studies in august 2021, researchers in the princess margaret cancer centre at the university health network published their discovery of a dormancy mechanism in key stem cells which could help develop cancer treatments in the future.