Given that tyrosine kinase inhibitor, targeted cancer therapy, was shown to be a robust treatment in EGFR mutation-positive NSCLC patients, the early and reliable detection of EGFR mutation as L858R and exon 19 deletion is greatly important for effective treatment, which implies the importance of diagnosis through liquid biopsy [19,20,21]. The gene discussed is EGFR; the disease is non-small cell lung carcinoma.