Cancer is usually accompanied by a certain hereditary predisposition, so a mother with cancer may pass it on to the next generation. Cancer is very different from hereditary diseases, which are caused by defects in one or more genes, and which may be passed on to the next generation, so that the next generation with the defects will also develop the same disease. However, as far as cancer is concerned, it has been found that genetic defects that can lead to the development of cancer are very rare. Although it is currently believed that there is a close relationship between cancer and genetic defects, whether or not cancer develops is affected by a number of other factors, and genetic defects related to cancer, even if inherited, may not necessarily lead to the development of the disease in the next generation. Because of this, although cancer is closely related to heredity, it is possible that certain genes related to cancer development may be passed on to the next generation. People whose mothers have cancer are more likely to develop cancer than those whose immediate family members do not have cancer.