Deleted in malignant brain tumors 1 protein (glycoprotein-340), a secreted glycoprotein, is considered a candidate tumor suppressor gene for brain, lung, esophageal, gastric, and colorectal cancers. Glycoprotein-340 plays roles in mucosal defense system, cellular immune defense and epithelial differentiation. Defects in glycoprotein-340 are involved in the development of glioma (GLM). Gliomas are central nervous system neoplasms derived from glial cells and comprise astrocytomas, glioblastoma multiforme, oligodendrogliomas, and ependymomas.