The interaction between lyophilized samples of ascorbic acid and some copper proteins (ceruloplasmin, cytochrome-c-oxidase, ascorbate-oxidase) has been investigated by means of ESR spectroscopy. The spectra obtained are identical to the one obtained with leukemic blood. The consequences of this for the molecular events occurring in cancer are discussed. The model proposed can explain the experimental findings reported thus far (such as change in spin concentration with the development of cancer, the presence of a high concentration of antioxidants etc.) as well as reconsile the two existing and seemingly contradictory hypothesis. Possible implications for lipid peroxidation and for the respiratory process are discussed.