New Delhi, Jul 08 (ANI): A new study has suggested that a drug used in stem cell therapy for certain cancers may also protect against cigarette smoke-induced lung injuries. The cancer drug, plerixafor, stimulates the immune system to release more of a certain stem cell (hematopoietic progenitor cells, or Hematopoietic progenitor cells (HPCs)) from the bone marrow into the bloodstream. The drug is used to treat some types of cancer that originate in the blood cells. Stem cells have the potential to develop into many different kinds of cells in the body and are involved in tissue repair. According to a previous research, lower numbers of HPCs in the bloodstream correspond to an increased severity of emphysema, a form of chronic obstructive pulmonary disease (COPD). COPD is a progressive lung disease that makes breathing difficult.