Cancer development and progression are multi-factor and multi-step processes. Scientists recognize that environmental, hereditary, and biological factors all play important roles in the development of cancer; it is doubtful that one process is involved in the etiology of all cancers. The exact cause of conversion of normal cells into cancerous ones is still not completely understood. An important factor is permanent alteration in the DNA of the cell, which is passed on to subsequent generations, but scientists do not know why some people succumb to a cancer and others do not. Cellular immunity undoubtedly plays some part in one's ability to stop the growth of cancerous cells; it is believed by some that most persons develop many small cancers in their lifetime but do not develop clinical signs because their defense mechanisms destroy the malignant cells and prevent their replication. Ultimately, the prevention of cancer depends upon knowledge of each person's risk factors for development of cancer, and that person's decision to avoid whenever possible those habits and practices that predispose to the disease. Each organ is made up of several different tissue types. Each type of tissue is made up of specific types of cells. Cancer can develop in just about any type of cell in the body. So there is almost always more than one type of cancer that can develop in any one organ. Medical conditions are often related to other diseases and conditions. Iron deficiency can be the result of numerous and multiple causes. In medicine, iron overload indicates accumulation of iron in the body from any cause. Primary tumors always develop at body sites of excessive iron deposits. Local/regional iron overload can be inherited or acquired. Iron disorders are inherited and can be confirmed with genetic testing. At the cellular level, cancer occurs when cellular iron overload affects cellular organelles. There are many types of organelles. Unfortunately, cellular iron overload can chaotically affect DNA, chromosomes, mitochondria, lysosomes, etc. The gene theory of cancer originated with Theodor Boveri’s suggestion in 1914 that cancer could arise from defects in the segregation of chromosomes during cell division. Otto Warburg argued that cancer should be interpreted as a type of mitochondrial disease. Lysosomal alterations are common in cancerous cells. The Father of Oncology recognizes that cancers are caused by iron-related genes or/and iron-related events. Chemical carcinogens, radiation, viruses, old age and some lifestyle factors non-genetically distort iron metabolism and create local/regional deposits within different tissues and organs. Clinical iron-deficiency methods will beat iron-related diseases (cancers).