From January 2018 to December 2022, a total of 222 patients with stage IIIB–IV NSCLC were enrolled for analysis, classified into three subgroups: 87 untreated lung squamous cell carcinoma (LUSC) cases, 60 treatment-naïve EGFR/ALK/ROS1 wild-type lung adenocarcinoma (LUAD) cases, and 75 EGFR-mutant LUAD cases with acquired resistance to EGFR-TKI. The gene discussed is ALK; the disease is lung adenocarcinoma.