CD274 and alveolar soft part sarcoma: Immunotherapy has become the standard of care in several advanced tumor types, but prolonged responses to anti-PD(L)-1) have only been observed in ultra-rare STS subtypes (such as alveolar soft part sarcoma, chordoma, etc.).2–6 In a phase II trial evaluating atezolizumab alone in 44 pretreated STS patients, the PFS was 1.6 months, with no patients surviving beyond 1 year and no objective responses observed.22 The SABR-PDL1 trial was developed to evaluate whether SBRT could potentiate out-of-field immunotherapy responses in a cohort of patients with advanced STS.