 Candida albicans is a fungus that can exist both as a harmless commensal organism and as a dangerous pathogen. It is able to maintain this balance by sensing the presence of a sugar called enacetylglicosamine, GLCNAC. When present, GLCNAC helps the fungus to grow as a commensal organism, but when absent it allows the fungus to switch into a more aggressive form that can cause serious illnesses. This ability to sense GLCNAC and respond accordingly is what allows the fungus to survive in different environments. This article was authored by Danden Yang, Mao Zhang, Chang Tzu, and others.