ETV1 and lung adenocarcinoma: Lung adenocarcinoma (LUAD) is one of the histological subtypes of lung cancer with a poor prognosis (Devesa et al., 2005); circ-ZNF609 was overexpressed in LUAD, acting as a sponge of miR-1224-3p to promote the cell proliferation of LUAD, which negatively regulated the expression of ETS variant transcription factor 1 (ETV1).