Abstract: Compositions for the treatment and/or prevention of cancer in a mammal by means of RNA interference are provided, together with methods for the use of such compositions. The compositions comprise a small interfering nucleic acid molecule (siNA) that suppresses expression of a target gene that: (a) is involved in an energy metabolism pathway, such as the glycolysis pathway, within a tumor cell; (b) is involved in the biosynthesis of nucleotides, in glycogen metabolism or is an electron carrier that works with ATP to provide metabolic energy; or (c) is involved in transport of sugars, amino acids, and/or water-soluble vitamins, control of intercellular pH, or drug transport within a tumor cell.