In contrast to Table 7, multivariate regression analysis showed that EGF rs1897990 genetic CT mutation and smoking were associated with lung adenocarcinoma in young patients (p = 0.043, OR = 1.309) and smoking status showed a statistically significant difference in susceptibility to lung adenocarcinoma (p = 0.002, OR = 2.465), indicating that smoking is a contributing factor associated with susceptibility to young lung adenocarcinoma. This evidence concerns the gene EGF and lung adenocarcinoma.