Following a large literature review (Wrangle et al. 2014; Yin et al. 2012; Yang et al. 2019; Li et al. 2020; Chen et al. 2020; Hulbert et al. 2017; Brait et al. 2012; Di Vinci et al. 2012; Hwang et al. 2015; Ooki et al. 2017; Zeng et al. 2019; Zhao et al. 2016; Song et al. 2015), we explored the performance of the DNA methylation of 7 genes including TAC1, CDO1, HOXA9, ZFP42, SOX17, RASSF1A and SHOX2 in the blood cfDNA samples in distinguishing lung cancer from benign nodules and healthy individuals. Here, TAC1 is linked to lung carcinoma.