Table 1.

Summary of four datasets after preprocessing.

Datasets	Sample sizes	Detection techniques	CpG sites
cfDNA set 1 [13]	4 LC/12 norm	Infinium EPIC array	752843
cfDNA set 2 [33]	29 LC/74 norm	RRBS	/
Tissue set 1 [34]	121 LC/12 norm	Infinium 450 K array	431802
Tissue set 2	832 LC/75 norm	Infinium 450 K array	337278

LC: lung cancer group; Norm: normal group. Detailed clinical information of participants is provided in the corresponding datasets.