Ascomycota of their hosts. Owing to their long evolutionary history, the Ascomycota have evolved the capacity to break down almost every organic substance. Unlike most organisms, they are able to use their own enzymes to digest plant biopolymers such as cellulose or lignin. Collagen, an abundant structural protein in animals, and keratin—a protein that forms hair and nails—, can also serve as food sources. Unusual examples include "Aureobasidium pullulans", which feeds on wall paint, and the kerosene fungus "Amorphotheca resinae", which feeds on aircraft fuel (causing occasional problems for the airline industry), and may sometimes block fuel pipes. Other species can
Nestin (protein) of actively growing pluripotent adult stem cells. Green fluorescent protein (GFP), whose expression is driven by the nestin regulatory element in transgenic mice, serves to mark hair follicle stem cells. These cells can differentiate into neurons, glia, keratinocytes, smooth muscle cells and melanocytes in vitro. Thus, hair follicle stem cells provide an effective, accessible, autologous source of stem cells for treatment of peripheral nerve injury. Nestin has recently received attention as a marker for detecting newly formed endothelial cells. Nestin is an angiogenesis marker of proliferating endothelial cells in colorectal cancer tissue. Nestin (protein) has been shown to interact with