CD274 and lung adenocarcinoma: Furthermore, to the best of our knowledge, this is the first report to analyze the relationship between TTF‐1 and PD‐L1 expression status based on PD‐L1 TPS ≥1% and ≥ 50% in advanced lung adenocarcinoma, and TTF‐1 expression status was significantly correlated with PD‐L1 expression status in advanced lung adenocarcinoma.