MRPL3 and lung adenocarcinoma: A prognostic model was constructed via LASSO regression, with its efficacy evaluated using calibration plots and decision curve analysis (DCA).The regulatory role of mitochondrial ribosomal protein large subunit 3 (MRPL3) in lung adenocarcinoma (LUAD) progression was validated through both <i>in vivo</i> and <i>in vitro</i> experiments.<h4>Results</h4>This model demonstrated reliable predictive performance across the testing set, validation set, and external validation cohorts.