Characteristics of cancer Determine whether each of the following statements about cancer is true or false 1. All tumors are cancerous. 2. The process of a tumor spreading is called metastasis. 3. Most cases of cancer are inherited as single-gene disorders. | 4. Somatic cells may develop mutations in cancer-causing genes. 5. Cancer begins when a cell divides less frequently than it should. 6. Oncogenes cause cancer when they are inactivated.