Next, we set the criteria of degree more than or equal to three to screen hub genes as biomarkers of circulating cfDNA in cancer by PPI analysis The present findings suggested that the 5-hmC levels of LCN2, LRG1, S100P, and TACSTD2 in circulating cfDNA may be used as potential noninvasive marker genes for CRC, resulting in several notable advantages. This evidence concerns the gene LCN2 and colorectal carcinoma.