Lung cancer cell with blebbing, coloured scanning electron micrograph (SEM). Lung cancer occurs when abnormal cells divide in a chaotic and uncontrolled manner resulting in the formation of a tumour in the lungs. The cell in this image is displaying blebbing. Blebbing is a bulge or protrusion of the plasma membrane of the cell which is visible on the cell surface. Blebbing may occur for a number of different reasons including during apoptosis (programmed cell death), or if a cell is undergoing physical or chemical stress. It also has important functions in cellular processes such as cell locomotion, playing a role in cell migration which may be an important factor in the spread of cancer. Lung cancer is more commonly found in older people and one of the most common factors associated with lung cancer is smoking. Other causes or risks associated with lung cancer are exposure to chemicals or pollutants or a family history of lung cancer. There are a number of treatments available for lung cancer depending on what type of lung cancer it is and the stage it is at. These may include surgery, chemotherapy and radiotherapy, immunotherapy and targeted cancer drugs. Magnification: x2400 when printed at 10cm wide.