Given that the difficulty of drug penetration into the CNS, tumor tissue may still remain sensitive to EGFR TKIs.[26,27] No EGFR mutation was detected in the patient, and we consider that it may be a false negative situation for concentration of ctDNA in peripheral blood too low to be detected after treatments, who had to rely on tissue biopsy for confirming the resistance mechanism. This evidence concerns the gene EGFR and neoplasm.