Proteins of secretions from 2 villous tumors of the rectum were fractionated by chromatography on DEAE-cellulose. Apart from the mucins, which were not studied in detail, the predominant protein component in both secretions was [gamma]A-immunoglobulin, which accounted for about 70% of the stainable protein in electrophoretic patterns on agar gel. Three minor protein components, which were apparently absent in the serum, were also identified. One of these was common to saliva and rectal secretions.