sentences:  Gp52 is a 52,000-dalton glycoprotein and gp36 is a 36,000-dalton glycoprotein.MMTV Env is of particular interest to researchers because of the discovery that it encodes an immunoreceptor tyrosine-based activation motif (ITAM) that has been shown to transform human and murine mammary cell in culture.This ITAM depolarizes epithelial acinar structures, thereby changing the phenotype of the cells and causing them to become cancerous.