ALK and lung adenocarcinoma: There is a significant difference in the incidence of combined EGFR and ALK changes between multifocal lung adenocarcinoma and single-focal lung adenocarcinoma, and an assessment of the relative abundance of EGFR mutations and ALK rearrangements in patients with multifocal lung adenocarcinoma with co-altered EGFR/ALK can distinguish mMPLC from intrapulmonary metastases (Fan et al., 2019).