PTPRR and non-small cell lung carcinoma: This approach is therefore a rational therapeutic strategy for KRASG12C-positive NSCLC, especially for tumors showing PTPRR downregulation.<h4>Significance</h4>The current study shows that downregulation of PTPRR induces EGFR activation and resistance to KRASG12C inhibitors in NSCLC, suggesting dual KRAS-EGFR blockade as a rational therapy.