MSH6 and synovial sarcoma: Additionally, some other variants of unknown significance were detected such as APC, KMT2D, and MSH6. Alterations in the APC gene have been previously detected in some cases of synovial sarcoma and were thought to contribute to the accumulation of β-catenin.[18] Likewise, the relationship between MSH6 expression and metastasis, response to chemotherapy, and survival time in patients with osteosarcoma have been investigated.[19] These studies indicate a potential role for APC and MSH6 mutations in sarcomas, where they may correlate with poor prognosis.