The present invention relates to methods and formulations for inhibiting, treating and preventing a malignant cell phenotype, cell, tumor and/or disease. Administration of nitric oxide mimetics, such as low doses, is sufficient to increase, restore or maintain nitric oxide-mediated signaling in cells so that malignant cell phenotypes, cells, tumors and/or diseases are inhibited or prevented. These methods and formulations are particularly useful in treating and preventing cancer in animals.