Keratinocyte cytokines.

It is now clear that keratinocytes produce a wide range of cytokines that can be regarded as important mediators of intercellular communication. A major emphasis has been placed on IL-1 because of its relationships with other cytokines and other differentiated tissues. Dysregulation of IL-1, IL-1 receptor, and inhibitory factors for IL-1 may cause imbalance of skin biology, leading to perpetuation of immune and inflammatory events. Interaction of IL-1 with other cytokines in vivo is also important in the understanding of the pathophysiology of skin diseases. More fundamental questions regarding the homeostatic significance of IL-1 in keratinocytes still remain to be answered.