The fungus Candida albicans is found in the gastrointestinal tract of about half of healthy adults with little if any effect, yet it also causes an oft-fatal blood infection among patients with compromised immune systems, including those with HIV/AIDS. New research helps show how this fungus gets the flexibility to live in these vastly different environments. The researchers, including Shen-Huan Liang, a pathobiology Ph.D. student, found that patient samples of the fungus frequently lack one copy of a gene that serves as a vital master regulator. In the lab, these cells can regularly switch to having a different set of traits, or phenotype, by losing the other copy. Read more.