Consistently, CTCs had a statistically significantly higher expression proportion score (%) than the matched primary NSCLC tissue (CTCs versus NSCLC tumor tissue: PD-L1: mean 39.20 (±3.72); median 36 (range 8–89) vs. 13.47 (±4.02); 0 (0–85) (p < 0.0001; non-parametric Wilcoxon signed-rank test for matched pairs); vimentin: 26.77 (±2.77); 23 (0–61) vs. 2.33 (± 1.64); 0 (0–40) (p = 0.0003); N-Cadherin: 24.47 (±3.04); 20 (0–63) vs. 4.33 (±2.28); 0 (0–50) (p = 0.0024)) (Figure 3). Here, VIM is linked to neoplasm.