ATRX mutations are more commonly present in male cancer overall (158) and in a number of cancers with sex differences in incidence and outcomes, including, glioblastoma, oligodendroglioma (159, 160), gastric cancer (161), and nonfunctional neuroendocrine tumors of the pancreas and other sites (162, 163), suggesting that biallelic ATRX expression may endow female cells with cancer protection. The gene discussed is ATRX; the disease is oligodendroglioma.