Its effect on EGFR-tyrosine kinase inhibitors (TKIs), especially the third-generation drug Osimertinib, and immune checkpoint inhibitors (ICIs) remains inconclusive.<h4>Case presentation</h4>A 45-year old male with lung adenocarcinoma progressed with liver metastasis after receiving pemetrexed and cisplatin as adjuvant chemotherapy. The gene discussed is EGFR; the disease is lung adenocarcinoma.