Table 2 displays the results of EGFR testing of cancer tissue and CTC samples. In the group before therapy (n = 28), the concordance rates were 88.2% and 90.9% in mutant EGFR and non-mutant EGFR groups, respectively. In the group under treatment (n = 52), the concordance rate between CTC and tissue was 95.5% for non-mutant EGFR. (Table 2A). Overall, the accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of EGFR mutation tests for CTCs were 89.3%, 88.2%, 90.9%, 93.8%, and 83.3%, respectively. This evidence concerns the gene EGFR and cancer.