FN1 and Arthritis: Using UG as a scaffold and the FN isoform containing the ED-B as a target, we have generated a fusion protein (L19-UG-TNFRII) able to selectively deliver a TNF-alpha inhibitor to inflamed tissues and we demonstrated that this fusion protein was able to significantly improve the severe symptomatology of arthritis in collagen antibody-induced arthritis (CAIA) mouse model.