This thesis represents a shift in approach from previous versions. It does not merely propose a hypothesis. It asserts a conclusion supported by evidence already published by the international scientific community. Cancer is predominantly viral. This is not an alternative theory. It is the logical and convergent reading of what medical, epidemiological and biological science has already demonstrated — in peer-reviewed studies, in international journals, signed by institutional researchers. The hypothesis is built on ten independent convergences: spousal concordance, occupational risk in surgeons, tumors in transplant recipients, indoor/outdoor gradient in six countries, migrations, leukodepletion, ancient Egypt, historical pandemics, COVID across 142 countries, India across 43 national tumor registries. The most devastating data point: the country ranking for cancer incidence and the country ranking for COVID incidence overlap perfectly. Same order. Two different diseases. One single variable: airborne transmission in enclosed spaces. All six Koch-Hill criteria are already satisfied with existing data. The author is not an institutional researcher. He did one thing only: asked the right questions. And used exclusively their own evidence.