The lungs are continuously exposed to external injurious agents, including surrounding air, bacteria, viruses, fungi, and certain chemical irritants. There must be a well-organized system to help our lungs stand against these harmful agents. There are a number of lung diseases responsible for significant morbidity and mortality throughout the world and they are under significant amount of attention from scientists. These diseases have become a challenge because of their increasing prevalence.

Chronic obstructive pulmonary diseases, which include emphysema and asthma, along with cystic fibrosis and pulmonary fibrosis, ultimately lead to compromise in functioning and permanent damage to the lungs. There are various treatment options available that can prolong the course of the disease; however, the last option in severe cases is lung transplantation. Not everyone can ...