A peptide, amino acid derivative, and/or organic acid extracted from blood serum, urine, or synthesized chemically, that inhibits the methylation of nucleic acids and the incorporation of L-glutamine into tumor-cell proteins. These agents also intercalate into DNA, leading to cell cycle arrest in the G1 phase and inhibition of mitosis and terminal cell differentiation. In addition, antineoplastons may inhibit RAS oncogene expression and activate the tumor suppressor gene p53, resulting in cell differentiation and apoptosis. (NCI04)