Besides, extent of capase-3 cleavage increased significantly in cells treated with SHK at the doses of 1.0 and 2.5 μg/mL (Figure 3(c)) but not at higher doses, suggesting that SHK activated caspase 3-mediated apoptotic signaling in a dose-dependent manner in A549 lung cancer cells. This evidence concerns the gene SHPK and lung cancer.