A cancer cluster means there are more cases of cancer in one certain area than there should be. It is like when a lot of people in your class get sick with the same thing, like the flu, at the same time. When people get sick with a disease like cancer, it can be really scary and it can make them feel really bad. Scientists try to figure out why some people get sick with cancer and why it is happening in one certain area. They study things like the environment, pollution, and what people are eating or drinking. By doing this, they hope to find ways to stop people from getting cancer and make them feel better if they already have it.