In 1991, a comprehensive review was published highlighting the importance of cytokines in
the immunopathogenesis of psoriasis. 1 Since then, many advances have been made re-
garding the critical role for pathogenic T cells as causing this common and enigmatic skin
disease. While epidermal keratinocytes are clearly involved as participants in establishment
of the appropriate cytokine milieu as presented earlier, more recent data point to T
lymphocytes as triggering the chain reaction of cellular and molecular networks that …