EGFR is a member of the tyrosine kinase (TK) family and is activated by dimerization upon binding to a ligand (epidermalgrowthfactorreceptortyrosinekinase (EGFR-TK)), which phosphorylates multiple tyrosine sites in the cell and activates a series of downstream signaling pathways by mediating EGFR-TK, which phosphorylates multiple tyrosine sites in cells, mediates the binding of corresponding adaptor molecules in cells, thereby causing the activation of a series of downstream signaling pathways that ultimately regulate cell growth, proliferation, differentiation, adhesion and migration. In lung carcinogenesis, mutations in EGFR are associated with the sensitivity of epidermalgrowthfactorreceptortyrosinekinaseinhibitors (EGFR-TKIs) and patient prognosis. The mutation sites identified are mainly located in exons 18 to 21. The mutation characteristics are: (1) exon 19 base deletion mutation; (2) exon 18 mutation; (3) exon 20 mutation or base insertion mutation; (4) exon 21 mutation. In China, exon 18 mutations and exon 19 deletions are more common. The results of numerous studies have shown that EGFR mutations are associated with a variety of factors, such as whether or not to smoke, gender, tumor pathology type and race. And the mutation rate is higher in female, non-smoking, and adenocarcinoma patients than in other populations in the East. The results of the IPASS study showed that EGFR mutations were associated with PFS and tumor remission, and the OPTIMAL study found that patients with EGFR mutations had higher efficiency, overall survival (overallsurvival) and progression-free survival after treatment with EGFR-TKIs compared with wild-type patients. (OS) and progressionfreesurvival (PFS) were longer. The above findings suggest that molecularly targeted therapy for patients with EGFR-sensitive mutations is the only way to benefit from EGFR-TKIs, and therefore EGFR mutation testing must be performed before NSCLC patients receive targeted drugs. mTOR mTOR, with a molecular weight of 289 kDa, is a large serine threonine kinase with a highly conserved structure among species. mTOR knockdown triggers early embryonic death. In normal cells mTOR regulates protein synthesis at the translational level in response to signals from nutrients, stress and growth factors to control processes such as cell movement, growth, division and apoptosis. Extracellular signaling molecules acting on receptor tyrosine kinases activate K-ras and PI3K and enable the latter to act on mTOR via downstream signaling. in mammals, mTOR signaling to SGK1 or S6K1 is dependent on the PI3K/Akt pathway. In normal cells mTOR is regulated in the PI3K/Akt signaling pathway. Akt activity largely determines whether the function of mTOR can be performed correctly, and phosphorylated mTOR activates two downstream substrates, Raptor and Rictor, which further regulate cellular translation. Among the downstream signals of mTOR, the most important signal sites are 4E-BP and p70S6K, a binding protein of eukaryotic initiator 4E, and p70S6K, an S6 kinase with a relative molecular mass of 70 kd. mTOR inhibitors bind to intracellular FKBP12 and inhibit protein translation initiation by altering the phosphorylation status of mTOR. Current studies have found that mTOR inhibitors have good antitumor activity and their toxic side effects are relatively low. However, mTOR inhibitors alone are considered to have only moderate antitumor activity, so current studies on this class of drugs tend to be combined with other antitumor drugs. It was found that EML4-ALK fusion genes rarely coexist with EGFR mutations, and most appear to be characterized by rejection, and resistance to EGFR-TKIs may be associated with the presence of EML4-ALK fusion genes.Koivunen et al. examined the expression of EML4-ALK fusion genes in 83 strains of human NSCLC cells and found that only H2228, DFC1032 and H3122 cell lines, and only the H3122 cell line could be inhibited by the EML4-ALK fusion gene inhibitor, allowing apoptosis to occur. New clinical trials reporting phase I clinical studies targeting EML4-ALK fusion gene inhibitors have found partial remission in 10 of 19 patients with advanced lung cancer. In the future, in order to achieve better outcomes in targeted therapy for patients with different molecular biological subtypes, lung cancer specimens need to be tested for EML4-ALK fusion genes along with EGFR gene mutations. The c-MET c-MET gene is located on human chromosome 7q21-q31, which contains 20 introns and 21 exons. The product of c-MET gene expression is a tyrosine kinase transmembrane receptor, which binds to hepatocytegrowthfactor (HGF) and activates downstream signaling pathways. c-MET protein and HGF in The expression of c-Met protein and HGF in NSCLC is related to stage, invasion, metastasis and poor prognosis. c-Met amplification is also associated with NSCLCTKI resistance. c-Met amplification copy number is closely related to patient survival, and the more amplification copy number, the shorter the patient survival and the worse the prognosis. Boccacio et al. found that human lung carcinogenesis was associated with mutation or amplification of c-MET gene, which could lead to tumor proliferation and inhibition of apoptosis, and was involved in tumor vascular growth and distant metastasis. MET gene amplification was increased, and c-MET may be a new targeted therapeutic option after EGFR-TKI secondary resistance. With the continuous progress of molecular biology, EGFR-TIK analogs have established an important position in NSCLC targeted therapy; the role of EML4-ALK fusion gene, mTOR and c-MET in NSCLC treatment is also becoming more prominent. In the future, we expect that new clinical studies will lead to promising results in targeted therapy and bring more options for targeted therapy for NSCLC patients.