This inflammation-inducible cassette was first used successfully to express luciferase (Luc) in vivo (55, –, 57) in response to i.p. LPS or turpentine, and later, to mitigate joint inflammation in rodent models of arthritis by intraarticular expression of IL-1R antagonist (58) or IL-10 (59). Here, IL1R1 is linked to arthritic joint disease.