Table 1. . Overview and comparison of the main viable analysis on circulating tumor cells, circulating-free DNA and exosomes in lung cancer.

Research field	Applications	CTCs	cfDNA	Exosomes
Mutations	Detection of point mutation, translocations, deletions, amplifications	Yes	Yes	Yes
Chromosomal abnormalities	FISH analysis	Yes	No	No
Epigenetic modifications	DNA methylation profiling	Yes	Yes	Yes
RNA transcription profiles	Determination of mRNA, ncRNA and RNA splice variant level	Yes	No	Yes
Protein profiles	Expression, phosphorylation and localization studies	Yes	No	Yes
Basic metastasis research	Cell morphology and clonality investigation, analysis in animal models	Yes	No	No

cfDNA: Circulating-free DNA; CTC: Circulating tumor cell; ncRNA: Non-coding RNA.