Pailler et al. [39] studied drug resistance mutations in CTCs isolated from 17 patients with ALK-rearranged NSCLC (14 were resistant to crizotinib, and 3 were resistant to loratinib) and studied more than 48 cancer-related genes and 14 ALK mutation regions at the single-cell level. This evidence concerns the gene ALK and non-small cell lung carcinoma.