Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Schematic rendition of the tonsillar crypt epithelium highlighting a disrupted basement membrane, a porous epithelial-subepithelial interface, and a thin and disrupted epithelium permitting exposure of the basement membrane to viral particles. Drawing by T. Phelps; reproduced from Reference 105. Abbreviation: HPV, human papillomavirus.
