A malignolipin-like material has been identified in the tissue and blood of both normal and tumor-bearing individuals of several species of animals and of man. The material isolated by us, which had chromatographic characteristics identical with those defining malignolipin (Kosaki), was found to be heterogeneous and to consist of lipid loosely associated with 3 amines, 1 of which was identified as l(+)-glutamic acid. The purified amines did not contain phosphorus. Picrates of the heterogeneous moiety or of the 3 amines contained large amounts of sodium and potassium picrates. The antigenicity of our fractions was studied. Preliminary examination of the blood of cancerous and normal human beings for malignolipin-like amines has been made.