In conclusion, the possible flow charts for deguelin-affected DNA damage in human lung cancer NCI-H460 cells are summarized in Fig. 5 which indicates that deguelin induced DNA damage followed by the inhibition of DNA repair associated gene expressions (mRNA) including BRCA1, DNA-PK, MGMT, p53, ATM and ATR, resulting in maintenance of DNA damage (Fig. 5). This evidence concerns the gene PRKDC and lung cancer.