This study describes a novel model of cancer. Cancer is caused, according to this model, by two toxic molecules, COF2 (carbonyl fluoride) and CS2 (carbon disulfide). COF2 acts as a catalyst and produces CS2. CS2 acts as a catalyst and produces COF2. Hence, the molecules COF2 and CS2 have the ability to reproduce each other, i.e. to create a chain reaction where COF2 and CS2 are multiplied. COF2 and CS2 are toxic. It is proposed that long-term cell exposure to COF2 and CS2 may disturb cell apoptosis and cause uncontrolled cell growth, i.e. cancer. Consequently, cancer is caused by a disease causing mechanism or agent and not by a pathogen. However, cancer can be initiated by e.g. a bacteria or virus that contains the molecules COF2 and CS2, wherein these molecules start a chain reaction producing COF2 and CS2 in the infected area and where the result can be cancer. The study describes why Fe2O3 (iron (III) oxide) may have a therapeutic effect on cancer.