Fig. 2

Airway epithelial cells are involved in lung repair and regeneration. The distribution of airway epithelia from the trachea, bronchi and bronchioles to alveoli is shown. Basal cells are progenitor cells of the lungs that are capable of self-renewal and differentiation into club cells, ciliated cells and goblet cells. Club cells can differentiate toward goblet cells, ciliated cells and ATII cells or toward basal cells. BASCs are located at bronchioloalveolar duct junctions (BADJs) and are involved in replenishing club cells and alveolar epithelial cells and promoting the repair and regeneration of lung tissues. ATII cells are progenitor cells of the alveolar epithelium that can self-renew and differentiate into ATI cells. By Figdraw (www.figdraw.com)