Lung Infographic (IMAGE) Cancer Research UK Caption The lungs of ex-smokers contained up to four times as many genetically healthy cells than those of current smokers. Credit The Sanger Institute / UCL Usage Restrictions For this story and with credit License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.