You've heard it before and you'll hear it again, smoking is very bad for you. We all knew that smoking increases your chances of getting cancer but what wasn't known was why and why in areas like the bladder or kidney where they were not exposed to smoke directly. The recent study has discovered reasons to why and has shown that DNA in the cancer tissues of smokers show mutations similar to each other but different to those of non-smoker cancerous tissues. Since mutations appear naturally throughout your life smoking obviously effects the risk of getting the mutations. But this study shows that the mutations contacted by smoking is a different type of mutation then that of non-smokers. What Alexandrov did, a scientist that ran the experiment, was run tests on cancerous tissues and both smokers and non smokers and studied the signatures the DNA was proposing, and evidently enough the signatures were the same for smokers and different for nonsmokers. This just another big break through to show people to not smoke. The test was run through 5,000 human samples representing 17 cancers for which smoking is a known risk factor. "'Tobacco smoking leaves permanent mutations - it erodes the genetic material of most cells in your body ,' says Alexandrov" (https://www.sciencenews.org/article/cancer-mutation-patterns-differ-smokers-nonsmokers?mode=topic&context=87). This study just opens up new information about the lethal disease cancer and even more information on the DNA and mutation part of the disease which is very helpful to cumulate more efforts to decrease the rate of cancer and decrease bad habits like smoking in the world.