Current treatments for chronic lung diseases are limited by their effectiveness over prolonged use. This project aims to assess the ability of relaxin, a reproductive hormone, to protect and reverse the symptoms associated with lung disease. Experimental models that induce asthma-like symptoms as well as human lung biopsy tissue were used to assess the effects of relaxin. Relaxin was tested alone and in combination with currently used treatments to see if they are able to improve the effectiveness of one another. These studies suggest that relaxin is a novel a bronchodilator and/or adjunct therapy to existing treatment.