RET and lung adenocarcinoma: Among the patients with lung adenocarcinomas with lymph node metastasis, the overall frequencies were as follows: EGFR mutations, 42.9% (120/280); ALK fusions, 10.7% (30/280); RET fusions, 3.6% (10/280); ROS1 fusions, 1.8% (5/280); and no mutations (wild type[WT]) in any of the 4 genes (WT/WT/WT/WT), 42.9% (120/280).