Interestingly, among the top 4 of most frequently mutated genes in all types of samples, rates of EGFR and TP53 mutations ranked top 2 among the cfDNA from any kinds of samples and tumor tissue DNA, while the frequency of RB1 mutation was the third ranking in cfDNA from urine (34%), sputum (30%), and tumor tissue (38%), however, which in plasma cfDNA (8%) was far less than that in tumor tissue and the rest of cfDNA (P = 0.003; Figure 4). Here, RB1 is linked to neoplasm.