In a C57BL/6 tumor xenograft mouse model of lung cancer, the addition of local 6 Gy in three daily fractions to anti‐PD‐L1 treatment effectively inhibited tumor progression compared to either anti‐PD‐L1 or radiotherapy alone, suggesting synergy between radiotherapy and anti‐PD‐L1. Here, CD274 is linked to lung carcinoma.