Wang S, et al. - Using data collected from 615 consecutive subjects who had undergone endobronchial biopsy (EBB) and been diagnosed with primary lung cancer from January 2014 through February 2018, a retrospective study was conducted to investigate the relationship of plasma apolipoprotein E (ApoE) with the risk of EBB-induced bleeding in patients with lung cancer. A non-linear correlation was found between plasma ApoE levels and the risk of EBB-induced bleeding. In patients with lung cancer, higher plasma ApoE concentrations (> 5.9 mg/dL) were an independent risk factor for hemorrhage during EBB.