A recent study suggests that ATRX haploinsufficiency cooperates with p53 deficiency to promote multiple types of carcinoma and sarcoma, including epithelioid sarcoma, angiosarcoma, undifferentiated pleomorphic sarcoma, papillary serous carcinoma, biliary carcinoma, malignant peripheral nerve sheath tumor, and high-grade glioma (14). This evidence concerns the gene ATRX and undifferentiated pleomorphic sarcoma.