Following treatment with 5 μM of KJ-28d and IR, the number of A549 and H1299 cells undergoing both early-stage (annexin V-positive/PI-negative) and late-stage (annexin V-positive/PI-positive) apoptosis increased significantly by 1.5-fold compared to KJ-28d alone, respectively, as shown in Figure 4B. In addition, KJ-28d plus IR treatment increased the cleavage of caspase-3 in both cell lines, as shown in Figure 4C. Taken together, these results indicated that KJ-28d enhanced both IR-induced DNA damage and apoptotic cell death in A549 and H1299 human NSCLC cells. This evidence concerns the gene CASP3 and non-small cell lung carcinoma.