P.E746_A750del gene is a type of exon 19 deletion in the EGFR (epidermal growth factor receptor) gene. The P.E746_A750del gene is a codon deletion located at positions 746 to 750. The deletion at this site can cause changes in the corresponding amino acid sequence in the epidermal growth factor receptor protein, altering the angle of the ATP-binding groove of the receptor tyrosine kinase, and altering the sensitivity of tumor cells to epidermal growth factor receptor tyrosine kinase inhibitors. P.E746_A750del gene mutation usually occurs in patients with lung adenocarcinoma and can be supplemented with corresponding targeted drugs for anti-tumor therapy.