Between the years of 2006 and 2010, one woman and seven men were enrolled in the study of skin cancer. Their ages ranged from 61 to 87 years. Informed consent was provided according to UCSF Committee on Human Research guidelines for large-scale genetic analysis. Data sharing is allowed so long as identity is not revealed. Board certified dermatopathologists confirmed the diagnosis of squamous cell carcinoma of the skin, from biopsies, for all study samples. Tissue was isolated using curettage before Mohs micrographic surgery. Control samples were obtained from adjacent normal skin.