MSH6 and osteosarcoma: MSH6 alterations were also seen in six patients in the uterine sarcoma cohort – two leiomyosarcoma, two sarcoma NOS, one undifferentiated uterine sarcoma, one low-grade endometrial stromal sarcoma –, five patients in the bone sarcoma cohort – osteosarcoma (n=4), Ewing sarcoma (n=1) –, and two patients in the GIST cohort.