CD274 (PD-L1) amplification was identified in 21 patients, including 17 patients in the STS cohort – dedifferentiated liposarcoma (n=8), undifferentiated pleomorphic sarcoma (n=5), sarcoma NOS (n=2), myxofibrosarcoma (n=1), pleomorphic liposarcoma (n=1) –, and four patients in the bone sarcoma cohort (all osteosarcoma). Here, CD274 is linked to myxofibrosarcoma.