¹Departments of Dermatology and Radiation Oncology, University of Michigan, and Ann Arbor Veterans Affairs Hospital, Ann Arbor, Michigan, USA

Correspondence: Dr James T. Elder, UM Dermatology, 1500 East Medical Center Drive, 3312 CCGC Box 0932, Ann Arbor, Michigan 48109-0932, USA. E-mail: jelder@umich.edu

Abstract

Interleukin-15 (IL-15) is a pro-inflammatory cytokine expressed in several inflammatory disorders. Zhang et al. (2007, this issue) report a significant genetic association between IL-15 and psoriasis, which may involve increased stability of IL-15 mRNA. Among its several activities, IL-15 stimulates the expression of IL-17 by T-cells. Together with recent genetic and therapeutic evidence implicating IL-23, these findings suggest a genetic basis for Th17-mediated inflammation in psoriasis.