Blockade of T lymphocyte costimulation with cytotoxic T lymphocyte-associated antigen 4-immunoglobulin (CTLA4Ig) reverses the cellular pathology of psoriatic plaques, including the activation of keratinocytes, dendritic cells, and endothelial cells. - Abrams,J.R.; Kelley,S.L.; Hayes,E.; Kikuchi,T.; Brown,M.J.; Kang,S.; Lebwohl,M.G.; Guzzo,C.A.; Jegasothy,B.V.; Linsley,P.S.; Krueger,J.G. (J Exp Med, 2000)