EGFR and neoplasm: The average plasma c-Met was 619.83 ± 166.92 ng/ml (95% confidence interval [CI]: 571.88 - 667.77) before EGFR-TKI treatment, decreased to 535.07 ± 135.37 ng/ml (95% CI: 496.19 - 573.95) at the time of the best tumor response, and then increased to 695.80 ± 339.98 ng/ml (95% CI: 598.15 - 793.46) with PD (P = 0.001).