ALK and lung adenocarcinoma: Similar to the results of the current study, EGFR mutated tumors more frequently had (multiple) extrathoracic metastases at diagnosis and tended to occur more frequently in the right upper lobe compared to EGFR wildtype and ALK rearranged tumors, while ALK positive lung adenocarcinomas were less frequently located in the right upper lobe compared to ALK wildtype tumors.