The use of PADM takes advantage of the biological characteristics of local cathepsin B release in the process of gastric cancer invasion and metastasis [21], demonstrating that the toxicity of PADM was significantly reduced under exposure to low levels of cathepsin B. In turn, safe doses of PADM prevented the peritoneal metastasis of gastric cancer in nude mice, reduced toxicity to the heart, liver, and kidney, and suppressed the overall toxic and side effects [8]. This evidence concerns the gene CTSB and gastric cancer.