EGFR and lung adenocarcinoma: Although it is known that anti-PD1/L1 monotherapy does not render significant benefit in patients with EGFR-mutant lung adenocarcinoma, whether the addition of anti-PD1/L1 therapy to chemotherapy can enhance chemotherapy efficacy for TKI-refractory EGFR-mutant lung adenocarcinoma patients is not clear.