PTEN, a dual protein and lipid phosphatase, is a tumor suppressor gene mutated in many human cancers. Keratinocyte-specific PTEN deleted mice were generated using Cre-LoxP system. The mutant mice exhibit wrinkled skin because of epidermal hyperplasia and hyperkeratosis and ruffled, shaggy, and curly hair. Histological examination of the mutant mice revealed that hyperkeratosis, hypergranulosis, and epidermal hyperplasia were present at birth and continued into adulthood. The cover features a microscopic photograph of the skin section of a three-month-old mutant mouse. For details, see the article by Suzuki et al. on page 674 of this issue.