In addition, we found evidence of low-frequency MET amplification by FISH (range: 2%–8% MET amplified cells) across the three MET polysomy osimertinib-resistant PDX models (LAT001_6B, LAT006_2B, and LAT015_6B) demonstrating early, subclonal MET amplification (Fig. 4A) occurring at a higher frequency than previously reported among untreated patients with EGFR-mutant NSCLC (21). Here, EGFR is linked to non-small cell lung carcinoma.