A phase-II clinical trial in head and neck squamous cell carcinoma (HNSCC) patients using nivolumab (anti-PD-1) with SBRT delivered in three fractions of 9 Gy to a single tumour lesion failed to improve overall survival (OS) or progression free survival (PFS), suggesting that the abscopal effect, if present, may be relatively rare.74 The gene discussed is PDCD1; the disease is head and neck squamous cell carcinoma.