In this exploratory study, we analyzed CD73 expression and related immune markers during sequenced EGFR-TKI treatment, including osimertinib, to identify potential biomarkers for CD73-based therapeutic opportunities in EGFR-resistant tumors.<h4>Methods</h4>Tumor specimens from patients included in a clinical trial (NCT02504346) evaluating osimertinib in <i>EGFR</i>-mutated EGFR-TKI pretreated NSCLC patients were analyzed. This evidence concerns the gene NT5E and non-small cell lung carcinoma.