Exciting news: Scientists at University of California - San Francisco accidentally discovered Previously it was thought that whereas they previously thought stem cells cause hairs to regrow after they fall out, that this only happens if Tregs (pron. tee-regs) are present. The researchers were investigating the role played by anti-inflammatory immune cells called Tregs in skin health generally.
https://www.ucsf.edu/news/2017/05/407121/new-hair-growth-mechanism-...