When the loss of ATRX and DAXX is detected, the chance of the tumor being ALT positive varies from 83% in leiomyosarcoma to 100% in osteosarcoma and liposarcoma, suggesting that mutation analysis of the ATRX and DAXX gene is a reliable predictor of the ALT positivity in certain cancers. The gene discussed is GPT; the disease is leiomyosarcoma.