Abstract: A transgenic non-human mammal with a disruption in its IL-21 receptor gene is provided, along with methods of using the transgenic non-human mammal.

Abstract: The present invention provides methods of screening for compositions useful for treating, ameliorating, or preventing fibrosis and/or fibrosis-associated conditions by measuring changes in the level(s) of IL-21 and/or IL-21 receptor (IL-21R) (e.g., the level of expression of IL-21 and/or IL-21R protein and/or mRNA, the level of activity of IL-21 and/or IL-21R, the level of interaction of IL-21 with IL-21R). The invention further provides antagonists of IL-21 or IL-21R for the treatment of fibrosis and/or fibrosis-associated conditions. Further provided herein are methods of diagnosing, prognosing, and monitoring the progress (e.g., the course of treatment) of fibrosis and/or fibrosis-associated conditions by measuring the level of IL-21 and/or IL-21R (i.e., the level of activity of IL-21 and/or IL-21R, the level of expression of IL-21 and/or IL-21R (e.g., the level of IL-21 and/or IL-21R gene products), and/or the level of interaction of IL-21 with IL-21R).

Abstract: This invention is based, at least in part, on the discovery of a novel nuclear protein which contains both PDZ and LIM domains, SLIM (STAT-interacting LIM). SLIM interacts with activated STAT molecules. The invention also provides methods of using these novel SLIM compositions. The invention also provides therapeutic methods involving the SLIM nucleic acid and protein molecules of the invention.

Abstract: A transgenic non-human mammal with a disruption in its IL-21 receptor gene is provided, along with methods of using the transgenic non-human mammal.