anything that is related to a person’s chance of getting a disease such as cancer. Some risk factors have a direct role in causing cancer, but in other cases the risk may be due to something else that goes along with the risk factor. For example, COPD (chronic obstructive pulmonary disease) is linked to higher risk of lung cancer, but this is because both can be caused by smoking. Different cancers have different risk factors. For example, excess exposure to sunlight is a risk factor for skin cancer; smoking is a risk factor for lung, mouth, throat, and other cancers. Some risk factors, such as smoking, can be controlled. Others, like a person’s age, can’t be changed. See also gene, mutation.