It was found that in U266 and NCI-H929 cancer cells, PT alone could moderately and the combination of PT/CuCl2 (2:1) dramatically inhibited the CT-like activity, while CuCl2 alone could not inhibit the CT-like peptidase activity (Figure 5c); in MCF-7 and SMMC-7721 cancer cells, PT could cause a dose-dependent inhibition of CT-like activity in the presence of 0.5 μM CuCl2 (Figure 5d). The gene discussed is LAP3; the disease is cancer.