The IL-29 is a newly described cytokine that is related to both the type-1 interferons and IL-10 family members.This novel cytokine is induced during viral infection and, like type-1 interferons, display significant anti-viral activity.In order to understand its function in more depth, we have examined the ability of IL-29 to regulate cytokine production by human umbilical vein endothelial cells (HUVECs).HUVECs exposed to IL-29 specifically upregulated IL-6, IL-8.This response was produced in a dose-dependent fashion.We have shown that IL-29, a cytokine produced in response to viral infection, activates HUVECs producing a restricted panel of cytokines and may therefore be important in activating innate immune responses at the site of viral infection.