The aim of the study is to characterized the T cell repertoire of individuals with immune mediated skin disease (e.g. psoriasis and mycosis fungoides). Peripheral blood with be collected from volunteers with psoriasis, mycosis fungoides and age matched controls. Fifteen tablespoons of blood will be collected prior to the initiation of treatment and again after the patient shows a clinical response to treatment. The time between blood draws will be no less than 3 months. There will be no more than two blood draws per patient. Blood samples will be used to determine the patient's HLA haplotype via PCR and DNA sequencing. After the patient's haplotype has been established the activated T cell repertoire will be analyzed for clonal expansions. Clonal expansions in the T cell repertoire will be determined by immunoscope analysis, which is a PCR based technique.