Lung cancer cells dividing, coloured scanning electron micrograph (SEM). Two daughter cells can be seen. The cells are undergoing cytokinesis which is the physical process of cell division which divides the parental cell into two daughter cells. At the end of cytokinesis the two daughter cells remain connected by the midbody for a short time. The midbody is organized by a set of microtubules and its main function is to localize the site of natural detachment (abscission) between the two daughter cells. Lung cancer occurs when abnormal cells divide in a chaotic and uncontrolled manner resulting in the formation of a tumour in the lungs. Lung cancer is the most common cause of cancer death in the UK. In 2016 it accounted for 21% of all cancer deaths in the UK. In terms of survival, approximately 5% will survive 10 years or more and 10% will survive 5 years or more. Magnification: x4500 when printed at 10 cm wide