Cover photograph (Copyright © 2003, American Society for Microbiology. All Rights Reserved.): Immunofluorescence of human keratinocytes expressing the E6 and E7 proteins of human papillomavirus type 38. Cells were fixed and subsequently stained with pan-keratin antibody (green) and vimentin antibody (red), which stain keratinocytes and fibroblasts, respectively. DNA was stained with Hoechst 33342 (blue). (See related article on p. 2195.)