TNFRSF9 and undifferentiated pleomorphic sarcoma: As our initial aim focused on identifying immunotherapy targets of relevance to UPS patients who progress after radiotherapy and surgery, of these 69 genes we searched the literature for previous publications on HAVCR2 (TIM-3), NT5E (CD73) and TNFRSF9 (4–1BB/CD137, referred to from this point as 4–1BB).