Abstract: The invention is a compound and method for enhancing the immune system. The compound is extensin or a combination of (a) pectin or polysaccharides found in the pectic molecule and (b) extensin. The method for cytotoxic enhancement of lymphocytes requires ingesting a therapeutically effective amount of extensin or a combination of pectin or polysaccharides found in the pectic molecule and extensin to enhance the activity of the immune system. The invention also relates to a method for preparing a therapeutically effective pharmaceutical for the cytotoxic enhancement of lymphocytes.