Current study indicates the advantages of NGS with targeted sequencing of CSF cfDNA in EGFR-mutant NSCLC.[26] Genotyping of CSF can indicate different response to osimertinib, reveal the genetic characteristic of osimertinib resistance in NSCLC patients with LM harboring EGFR-mutated.[27]. This evidence concerns the gene EGFR and non-small cell lung carcinoma.