EGFR and neoplasm: Among the 93 tumor-tissue EGFR M+ patients, the median cfDNA concentration of the 57 plasma EGFR M+ patients was 11.61 ng/mL (range 1.63-406.91), while that of the 36 plasma EGFR M- patients was 7.73 ng/mL (range 1.01-29.76); this difference was statistically significant (P = 0.003) (Figure 2B).