Several studies have revealed that the ALT-positive phenotype correlates perfectly with the inactivation of alpha-thalassemia/mental retardation syndrome X-linked (ATRX) or death domain–associated protein (DAXX) in pancreatic neuroendocrine tumors (PanNETs), astrocytomas, and leiomyosarcomas (Heaphy et al. 2011; Marinoni et al. 2014; Abedalthagafi et al. 2013; Liau et al. 2015). The gene discussed is GPT; the disease is leiomyosarcoma.