D-Valine is an isomer of the essential amino acid L-Valine. D-Valine has been used as a selective agent in epithelial cells in culture since it inhibits cells that lack the enzyme D-amino acid oxidase. D-Valine has also been shown to inhibit proliferation of contaminating fibroblasts in smooth muscle cells from human myometrium. D-Valine solution showed tumor growth inhibition and improvements of the nutritional status in AH109A hepatoma-bearing rats.